Mega Deck Flashcards

Question

How is acceleration defined?

Answer 1

Acceleration is the rate of change of velocity.

Answer 2

Speed is the rate of change of distance. Velocity is the rate of change of displacement.

Answer 3

Ball is moving to the right and speeding up.

Answer 4

Ball is moving to the left and speeding up.

Answer 5

Ball is moving to the right and slowing down.

Answer 6

Ball is moving to the left but slowing down.

Answer 7

Only if the velocity vector is also acting to the right.

Answer 8

A constant velocity.

Answer 9

An increasing velocity (acceleration)

Answer 10

A decreasing velocity (decceleration)

Answer 11

A negative velocity (travelling back to where it started)

Answer 12

A constant acceleration.

Answer 13

An increasing acceleration.

Answer 14

A decreasing acceleration.

Answer 15

A negative acceleration.

Answer 16

A ball bouncing off a surface (Dotted lines represent the bounce) (Red lines represent the ball accelerating towards the ground)

Answer 17

Constant acceleration of 9.81ms-2

Answer 18

Displacement takes direction into account. It should be...

Answer 19

Because the **acceleration (gradient) is changing**

Answer 20

Only **weight is acting on the object** It has a constant **acceleration of 9.81ms-2** acting downawards (on Earth)

Answer 21

They both hit the ground at the same time... Both in freefall so accelerate at 9.81ms-2 **Vertical motion independent of horizontal motion**

Answer 22

Initial velocity and final velocity are not 0

Answer 23

At the peak of a parabola ## Footnote **Not at the start or end**

Answer 24

Resolve the velocity into vertical and horizontal components and fill out the corresponding SUVATs

Answer 25

The acceleration is only 9.81ms^-2 if the object is in freefall

Answer 26

When the **acceleration = 0 (constant velocity)** Or to work out an **average speed**

Answer 27

When **acceleration is constant** Or if object has stages of constant acceleration

Answer 28

Uniform circular motion

Answer 29

Minimum tension at the top Maximum tension at the bottom

Answer 30

The lift force is comprised of a horizontal and vertical component. The horizontal component provides the centripetal force causing it to turn.

Answer 31

The resultant force that makes the object move in a circle

Answer 32

Simple harmonic motion

Answer 33

The time for one complete cycle of oscillation.

Answer 34

Velocity as cos(x) Acceleration as -sin(x)

Answer 35

It oscillates with a constant amplitude because there is no friction acting on it. (Its energy is constant)

Answer 36

The frequency of free oscillations of an oscillating system.

Answer 37

Making an object oscillate at a frequency that is not it’s natural frequency

Answer 38

When the **frequency of driving force** or oscillation **matches** the **natural frequency** of the system.

Answer 39

An increase in amplitude of the system’s oscillation.

Answer 40

The term used to describe the removal of energy from an oscillating system.

Answer 41

System not allowed to oscillate. Slowly returns to equilibrium.

Answer 42

The oscillating system returns to the zero position of the oscillation after one quarter of a time period.

Answer 43

The angle through which an object in circular motion travels in a given time

Answer 44

Light Heavy Critical

Answer 45

The system oscillates over a long time frame before coming to rest. The amplitude of the oscillations exponentially decay.

Answer 46

**Always towards the centre**

Answer 47

A **velocity** needs to be acting **perpendicular** to a **resultant force**

Answer 48

Set R=0 (or tension if ball on string) And rearrange for v

Answer 49

Set reaction R=0 Then rearrange for v

Answer 50

1. Set vertical component of force = weight 2. Work out horizontal component using trig 3. F_centri = horizontal component

Answer 51

There must be a vertical component of the tension to match the weight Otherwise ball is not in vertical equilibrium

Answer 52

1. Acceleration must be proportional to displacement 2. Acceleration must be opposite to displacement

Answer 53

**Time period is independent of amplitude**

Answer 54

1. Mass on the end of the spring 2. Spring constant (stiffness) of spring

Answer 55

1. Length between top of string and centre of bob 2. Gravitational field strength

Answer 56

**÷60 to convert to rps** (revolutions per second) Then set **rps = frequency**

Answer 57

Amplitude decreases (as it loses energy) But time period remains constant

Answer 58

The number of complete oscillations per second

Answer 59

Its linear **velocity does not change in magnitude** But is **constantly changing in direction**

Answer 60

P and Y because they have the **same length** So **natural frequency of y matches** frequency of driving force from **P**

Answer 61

Circular motion does not happen (Eg car skids off the road or moves to a higher radius)

Answer 62

Circular motion happens (eg friction is large enough to keep car on track)

Answer 63

The **maximum displacement** of an obejct/particle/point **from equilibrium position**

Answer 64

x=Acos(wt) -\> displacement in SHM when x=A when t=0 x=Asin(wt) -\> displacement in SHM when x=0 when t=0

Answer 65

When projected onto a flat surface, yes it does

Answer 66

Low amplitude oscillations With 0 phase difference.

Answer 67

**Resonance occurs** Large amplitude oscillations π/2 radians out of phase

Answer 68

Low amplitude oscillations With phase difference of π

Answer 69

If no resultant force acts on a body, then it will either remain at rest, or continue moving with constant velocity (no acceleration)

Answer 70

The rate of change of momentum (acceleration) of a body is directly proportional to the resultant force acting on it ## Footnote **F_res∝ a**

Answer 71

When two objects interact, they exert an equal and opposite force on each other and the forces are of the same type

Answer 72

There is **no resultant force** so it will continue moving at a constant velocity. It won't accelerate.

Answer 73

In F=ma, **F must be the resultant force!!!**

Answer 74

As it speeds up, air resistance increases, decreasing the resultant force. Eventually air resistance = driving force, F_res=0 so a=0.

Answer 75

1. Tension always acts away from the contact points 2. Tension is constant throughout the rope/wire/ cable

Answer 76

There will always be **air resistance** opposing the weight (Apart from when v=0)

Answer 77

The drag force = driving force (or weight) so **F_res=0** and so **a=0**

Answer 78

* Fluid density * Shape of object * Cross sectional area of object * Velocity of object

Answer 79

The object is colliding with more air molecules **per second**

Answer 80

The **acceleration is not constant** so you **cannot use SUVATs** Instead use area under graph

Answer 81

Direction must be taken into account (as momentum is a vector)

Answer 82

1. Rate of change of momentum 2. Impact force x impact time

Answer 83

The **change of momentum** or **impulse**

Answer 84

For a system of interacting objects, **the total momentum remains constant...** **…**provided **no external resultant force acts**

Answer 85

Total momentum is always conserved Total energy is always conserved **Kinetic energy is only conserved if collision is elastic**

Answer 86

A collision where kinetic energy is conserved (as well as momentum)

Answer 87

You have to c**alculate kinetic energies separately** for each object

Answer 88

The total momentum = 0

Answer 89

Consider the cylinder made by a liquid's flow after 1 second Where the **length of the cylinder = velocity of the fluid** And use density equation to get volume of cylinder

Answer 90

1. Split into boxes 2. Count the boxes (pairing up incomplete boxes) 3. Multiply number of boxes by area of each box

Answer 91

Energy cannot be created or destroyed, only transferred from one type to another.

Answer 92

When the **force does work on the object (same direction as movement)**

Answer 93

By **doing work against a force** (usually frictional)

Answer 94

In W=Fs you **multiply the parallel components**

Answer 95

The **components must be parallel**

Answer 96

0 because the weight is **perpendicular to the movement** So there is **no parallel component to displacement**

Answer 97

Both hit at the same time because they both accelerate at 9.81ms^-2

Answer 98

Energy equivalency (only works when air resistance = 0)

Answer 99

The rate of transfer of energy or The rate at which work is done (Measured in **Watts [W]**)

Answer 100

For P=Fv, **F is not the resultant force**

Answer 101

**No,** because some GPE is converted to thermal and kinetic energy of the snow (working against friction)

Answer 102

A collection of 6.02×10²³molecules (Avogadro's constant)

Answer 103

The mass of each mole (every 6.02×10²³molecules) Eg for He each mole has a mass of 4g

Answer 104

**Add up the nucleon numbers** (14+16+16=46gmol^-1)

Answer 105

**N = n × N_A** (Number of molecules = moles × Avogadro's constant)

Answer 106

The mass of each molecule of the substance **m = M/N** (molecular mass = total mass / number of molecules)

Answer 107

**M = n × m_r** (Total mass = moles × molar mass)

Answer 108

**T(K) = T(°C) + 273**

Answer 109

The point at which an ideal gas exerts no pressure (0K, -273°C, molecules have no kinetic energy)

Answer 110

The pressure in a gas is inversely proportional to the volume it occupies **at a fixed temperature** **and a fixed mass of gas** (P ∝ 1/V)

Answer 111

Plot a graph of P against 1/V Should be a straight line **passing through the origin**

Answer 112

Volume a gas occupies is directly proportional to the temperature of the gas **at a fixed pressure** **and a fixed mass of gas** (V ∝ T)

Answer 113

Plot a graph of V against T Should be a straight line **passing through the origin**

Answer 114

Note: x-intercept represents absolute zero

Answer 115

The pressure of a gas is directly proportional to the temperature of the gas ## Footnote **at a fixed volume** **and a fixed mass of gas**

Answer 116

Plot a graph of P against T Should be a straight line **passing through the origin**

Answer 117

Note: x-intercept is absolute zero

Answer 118

If the **mass of the gas is constant**

Answer 119

Calculate the **area under the curve**

Answer 120

P = F / A (Pressure = Force / Area)

Answer 121

* The gas molecules collide with the container walls changing their momentum. * This creates a force on the molecule and the wall * Exerting a pressure

Answer 122

1. **Volume of the molecules** must be much **smaller** than the **volume of the gas** itself 2. The **intermolecular forces** are **negligible** 3. The **collision time** of molecules with each other and the walls is much **less than** the **time between** them 4. The collisions are **elastic** (no loss in KE) 5. The molecules' motion is **random**

Answer 123

* Air molecules are moving randomly * They collide with the smoke changing momentum and exerting a force on the smoke particles * If at one moment there are more collisions on one side than the other * The smoke particle has a resultant force so accelerates in that direction

Answer 124

* When volume of container is decreased * More collisions **per second** * So total momentum change bigger (▲p) * So force exerted bigger * So pressure bigger (From P = F/A)

Answer 125

* When temperature is increased * Volume increases to increase the distance travelled between collisions * Molecules have greater kinetic energy but travel further so frequency stays same * Change in momentum (▲p) stays constant * So pressure is constant (P = F/A)

Answer 126

* As temperature increases * The average kinetic energy of the molecules increases * Increasing the number of collisions **per second** with container walls * So greater change in momentum * Greater force and pressure exerted (P = F/A)

Answer 127

1. Square the speeds and add up 2. Take a mean of the squares 3. Square root the value

Answer 128

c_ms = (c_rms)²

Answer 129

Molecules have a **range of kinetic energies**. So temperature of the gas is a measure of the **average kinetic energy.**

Answer 130

Multiply each by the **number of molecules of the gas**.

Answer 131

* There is a **net flow** of thermal energy from the hotter object to the colder object * **Until** both objects are at the **same temperature** * And there is now **no net flow of thermal energy**

Answer 132

The energy required to increase 1kg of a substance by 1K [Jkg^-1K^-1]

Answer 133

To calculate the **mass flowing per kg** of a fluid

Answer 134

The thermal energy is used to **break some of the intermolecular bonds** (solid → liquid) or the **rest of the intermolecular bonds** (liquid → gas)

Answer 135

The energy required to change the state of 1kg of a solid to a liquid **at its melting point.**

Answer 136

The energy required to change the state of 1kg of a liquid to a gas **at its boiling point.**

Answer 137

Haven't considered the change of states. Need to break it into 3 equations:

Answer 138

The mass per unit volume. [kgm^-3]

Answer 139

Whatever you do to the unit, you **do the same to the prefix** (eg 5cm³ = 5x(10^-2)³m³= 5x10^-6m³)

Answer 140

1. Read off the volume from the **beaker or measuring cylinder** without and with the object submerged in water 2. The difference in volumes is the volume of the solid 3. Measure the mass **using a balance** Calculate density using ρ=M/V

Answer 141

1. Work out the mass of each and the volume of each 2. Add together to get the total mass and volume 3. Then do the density calculation

Answer 142

When a material is stretched, its extension is proportional to the force applied, up **until the limit of proportionality** F=kx

Answer 143

The point at which the material stops obeying Hooke's law. The graph is no longer a straight line.

Answer 144

The point at which when stretched further the material no longer returns to its original length (there is a permanent extension)

Answer 145

**Gradient** → The **spring constant** (must be taken before limit of proportionality) **Area under line →** The strain energy stored loading the spring or energy released unloading the spring

Answer 146

Limit of proportionality is the point at which a stretched spring (or wire) stops obeying Hooke's law. The elastic limit is the point at which it doesn't return to its original length when unloaded.

Answer 147

Yes, because it has **not passed the elastic limit**

Answer 148

A material with a **large plastic region**.

Answer 149

A material with a small plastic region.

Answer 150

The point at which a material breaks

Answer 151

It still returns to its original length when unloaded.

Answer 152

**Gradient** → **Young's modulus** (before the limit of proportionality) **Area** → strain **energy per unit volume**

Answer 153

The **rate of flow of charge**

Answer 154

Divide charge by the charge of each electron (6.25x10¹⁹)

Answer 155

**Conventional current** flows from the +ve terminal to the -ve terminal **Electron flow** shows the direction the electrons flow, from -ve to +ve

Answer 156

Increasing potential difference increases the current Increasing resistance decreases the current

Answer 157

The current flowing through a metallic conductor is proportional to the potential difference applied across it **at constant temperature**

Answer 158

When the **component has a fixed resistance** (eg a fixed resistor at a constant temperature, or a filament at a low current)

Answer 159

The **work done** (energy transferred) **by** **each coulomb of charge** moving between two points (Eg a 12V battery adds 12J of energy to each coulomb of charge passing through)

Answer 160

If there is an available path with **0 resistance** **Current → ∞** And the circuit **heats up**

Answer 161

Resistance is **not calculated using the gradient (**of a tangent**) of an I-V graph!!!** Instead just **use the voltage and current at that point**

Answer 162

As current increases, temperature of filament increases This **increases lattice ion vibrations**. Which increases the number of **collisions per second with electrons.** So **resistance increases.**

Answer 163

The **straight line passing through the origin** ## Footnote **proves that current ∝ voltage**

Answer 164

* As the potential difference increases **weakly bound electrons** in the conductor gain energy * After the threshold pd, some **electrons become free** to carry a current * The **lattice vibrations** still increase but this is **less significant**

Answer 165

No current flows until the breakdown voltage is reached (**~**50V) The diode breaks and all current flows through

Answer 166

**Parallel circuits have junctions** (3 or more wires connect)

Answer 167

Voltmeters have ~ **∞ R so no current flows through**

Answer 168

**P.D is shared** across the components (by resistance) **Current is constant** throughout

Answer 169

**P.D is shared** across the components (by resistance) **Current is constant** throughout

Answer 170

**P.D is same for parallel branches** **Current separates at junctions** (according to branch resistance)

Answer 171

At any junction in a circuit the **sum of the current flowing into the junction** is **equal** to the **sum of the current flowing away from it.**

Answer 172

In any complete “loop” of a circuit the sum of p.d’s equals the source p.d.

Answer 173

Add up their resistances

Answer 174

Use the following equation…

Answer 175

The **total resistance is always less** than the smallest resistance

Answer 176

No, because the **resistance of each branch is different**

Answer 177

No, because the **resistance of the components are different**

Answer 178

* The power delivered is the same * But they take longer to run flatter

Answer 179

A circuit with **2 or more resistors connected in series** with a power supply. (usually one is a thermistor or LDR)

Answer 180

As **temperature increases, resistance decreases**

Answer 181

As **light intensity increases, resistance decreases**

Answer 182

* Simpler circuit * Current constant throughout * But cannot get 0V across bulb

Answer 183

* Bulb can receive full range of voltage 0V → V_source * Current through bulb can be reduced to 0A * But maximum current is lower

Answer 184

* Increased length → increased resistance * Increases cross sectional area → decreased resistance * Increased resistivity (using different material) → increased resistance

Answer 185

Assume it to be a cylinder (unless told otherwise) ## Footnote **A=∏r²**

Answer 186

There are **more paths for the electrons to propagate**

Answer 187

* Work out the P.D of each component * Make a loop connecting the branches * Subtract the PDs of one branch from the other

Answer 188

A material with **0 resistance at and below the critical temperature**

Answer 189

* The **lattice ion vibrations reduce to 0** * So **electrons can pass** through **without collision**

Answer 190

* Transmit large currents with 0 resistance * So negligible thermal energy losses * Used to create high power magnets → MRI machines * High processing power circuits → Supercomputers

Answer 191

The **potential difference across the terminals** when **no current** is flowing through

Answer 192

The **potential difference** across the terminals **when a current** is flowing through

Answer 193

The potential difference used up pushing a current through the battery (**v_lost= emf - TPD**)

Answer 194

Treat the internal resistance as another resistor in series with the components Then solve as a regular circuit (using ohm's law, kirchoff's laws, P=IV etc)

Answer 195

Light incident on a **metal surface** causes **electrons to be emitted from the surface**

Answer 196

Blue and green light are **above the threshold frequency of this metal** So the **photons of light have an energy \> work function (****φ****)**

Answer 197

The red light **photons are below the threshold frequency** So the **energy of each photon \< work function (****φ****)**

Answer 198

**Electrons** in the metal interact with photons in a **1-1 interaction** They only absorb photons which have an **energy \> work function (****φ****)**

Answer 199

1. Both light sources have **frequency above the threshold frequency (f₀)** of the metal 2. The electrons emitted due to the blue light have a **greater maximum kinetic energy** (because blue photons have a greater energy from E=hf)

Answer 200

The **minimum frequency of the incident light** needed to cause electrons to be emitted from the surface

Answer 201

1. The green light is above the threshold frequency so the photelectric effect happens 2. The brighter lamp causes **more photons of light to collide with electrons** so **more photons are emitted per second** (But the electrons have the same maximum kinetic energy)

Answer 202

1. **Increase the frequency** of the light source 2. **Increase the brightness** of the light source

Answer 203

1. Y-intercept = - work function 2. X-intercept = threshold frequency 3. Plancks' Constant

Answer 204

1. Y-intercept (φ) decreases 2. X-intercept (f₀) increases 3. **But the gradient (h) is constant**

Answer 205

Electrons interact with the photons in a **1-1 interaction** But only if the photon has an energy \> work function **No red light photons have an energy \> work function** So electron **emission will never occur**

Answer 206

The **minimum energy** required to **liberate an electron from the surface of a metal**

Answer 207

Difference between the energy of each photon and the work function (φ)

Answer 208

1. A charged rod transfers additional electrons to the plate causing repulsion between the stem and gold leaf 2. Electrons are liberated from the metal surface (by light above f₀) so the stem and leaf become neutrally charged again

Answer 209

The **kinetic energy gained by 1 electron passing through a potential difference of 1 volt**

Answer 210

**eV → J : multiply by 1.6x10^-19J** **J → divide by 1.6x10^-19J**

Answer 211

1. Connect the system to a circuit 2. Place a battery opposing the current produced by the emitted electrons 3. Measure the **stopping potential** when the total current = 0 4. **E_kmax= eV_s**

Answer 212

**Electrons deeper down require more energy to rise to the surface** before being liberated (Electrons at the very top of the surface are emitted with maximum kinetic energy)

Answer 213

1. Continuous - Produced by **blackbody** 2. Emission - Produced by **an excited gas** 3. Absorption - Produced by a **continuous spectrum passing through a cold gas**

Answer 214

* Electrons can only travel in **allowed orbitals (energy levels)** * Electrons can emit or absorb energies to **instantaneously transition between orbitals** * Electrons **cannot exist between orbitals**

Answer 215

It must **absorb an energy = the difference between levels** (By photon or electron collision)

Answer 216

It must **emit an photon of energy = the difference between levels**

Answer 217

1. Each element has a different set of orbitals (with different energy levels) 2. So each element has a different set of electron de-excitation energies 3. The different de-excitation energies produce photons with different frequencies (E=hf)

Answer 218

1. Calculate then energy difference between the energy levels 2. Convert energy difference to Joules 3. Convert to f or λ (E=hf or E=hc/λ)

Answer 219

The energy required for an electron to to become liberated from an atom ## Footnote **Equal to the energy of the ground state**

Answer 220

**Never use work function when talking about energy levels**. Ionisation and work function are different.

Answer 221

* Photon energy = Difference between energy levels * Electron energy ≥ Difference between energy levels

Answer 222

6 possible transition so 6 different photons

Answer 223

So a large enough current (of incident electrons) can be sustained

Answer 224

1. Mercury atoms excite by absorbing electrons from the current 2. When the Mercury atoms de-excite they emit UV photons 3. UV photons are absorbed by and excite the phosphor coating 4. When the phosphor coating de-excites it emits visible light

Answer 225

When their **Debroglie Wavelength is similar to the size of the gap** they are passing through

Answer 226

Wave-Particle duality Electron diffraction through graphite to form maximas (bright rings) and minimas (dark rings)

Answer 227

**The electron** (It has the same magnitude of charge as the proton but a much smaller mass)

Answer 228

Neutron → 0 specific charge so zero deflection Electron → Greatest specific charge so greatest deflection Proton → Smaller deflection in opposite direction as specific charge smaller and opposite

Answer 229

Divide the total charge of the protons by the total mass of nucleus (Protons + Neutrons)

Answer 230

Charge of the ion (Protons - Electrons) divided by total mass of ion

Answer 231

An atom with the 1. **same number of protons** 2. **Different number of neutrons**

Answer 232

If the nucleus has: 1. too many or too few protons 2. Too many nucleons 3. Too much vibrational energy

Answer 233

A nucleus ejects a helium nucleus (2 protons and 2 neutrons) Decreasing its nucleon number by 4 And its proton number by 2

Answer 234

A **neutron turns into a proton** **Ejecting a fast moving electron (****β^-****) and an anti-electron neutrino**

Answer 235

A **proton turns into a neutron** **Ejecting a fast moving positron (****β⁺****) and an electron neutrino**

Answer 236

The **nucleon number must not change**

Answer 237

α and β⁺ → Deflect in same direction but β⁺larger (greater specific charge) β^- → Equal and opposite deflection to β⁺(Equal and opposite specific charge) γ → No deflection (no specific charge)

Answer 238

A particle with the: 1. **Same mass** 2. **But equal and opposite charge**

Answer 239

A **particle collides** and annihilates with its correspond **antiparticle** And their **mass energy (E=mc²) is converted to radiation energy** **Producing at least 2 gamma photons**

Answer 240

To conserve momentum Before annihilation p_total= 0 AFter annihilation **p_total = 0 (can't be achieved with one photon)**

Answer 241

A gamma photon (with energy ≥ 2 **×** mass energy) spontaneously creates a particle, anti-particle pair

Answer 242

The energy of the gamma photon ≥ Mass energy of the particle anti-particle pair (Any excess energy is used a kinetic energy for the particles produced)

Answer 243

During Beta decay the emitted β^-had less energy than expected so another particle carried the rest of the energy

Answer 244

1. Strong 2. Weak 3. Electromagnetic 4. Gravitational

Answer 245

Holds nucleons together in the nucleus * By opposing the electromagnetic repulsion of the protons * By attracting nucleons at small distances but repelling the, at very small distances Gluons (between quarks), or pions (between hadrons)

Answer 246

**Very repulsive over short distance (0-0.5fm)** **Attractive over larger distances (0.5fm \< d \< 3fm)** **Negligible beyond 3fm**

Answer 247

Acts between all **particles with charge** ## Footnote **Exchange particle is the photon**

Answer 248

Particles or objects **with mass**

Answer 249

Acts between leptons and hadrons and causes the decay of hadrons (by changing quark structure)

Answer 250

NOTE: Each of the leptons and and quarks has an corresponding anti-lepton and anti-quark

Answer 251

Up, Up, Down

Answer 252

Up, down, down

Answer 253

Both are leptons, muon is much heavier than the electron, produced in cosmic ray showers

Answer 254

**Particles that are made up of quarks**

Answer 255

Both are hadrons (made up of quarks) But **Baryons are made up of 3 quarks** And **Mesons are made up of 1 quark 1 anti-quark**

Answer 256

**Both are exchange particles** But **W bosons mediate the weak force, Photons mediate electromagnetic** W bosons carry charge of +1 or -1, Photons have no charge W bosons have mass, Photons are massless

Answer 257

**Both mediate the strong force** **But gluons act between quarks, Pions act between hadrons** (to keep the nucleus together) Gluons have no mass, Pions have mass

Answer 258

It **creates the Higgs field** Which **gives mass to particles**

Answer 259

* **Total momentum** * **Total energy** * **Charge** * **Baryon** * **Lepton number** NOTE 1: **Kinetic energy** is conserved in **elastic collisions** NOTE 2: **Strangeness** is conserved in all interactions **apart from weak**

Answer 260

They are made of **1 quark and 1 anti-quark** (mesons) ## Footnote **They have non-zero strangeness** **Produced by strong interactions, Decay (into pions) by weak interactions**

Answer 261

They are **made up of 1 quark and 1 anti-quark (mesons)** ## Footnote **They have strangeness = 0**

Answer 262

The **electron** and the **proton**

Answer 263

* Communication for high latitude regions (close to the poles) * Espionage (spying) * Meteorology (weather)

Answer 264

**Baryons = +1** **Anti-Baryons = -1** **All other particles (including mesons) = 0**

Answer 265

**Leptons = +1** **Anti-Leptons = -1** **All other particles = 0**

Answer 266

0! Only muons and muon neutrinos have L_muon= +1

Answer 267

0! Only electrons and electron neutrinos have L_electron= +1

Answer 268

Both are **uniform** (constant field strength) ## Footnote **Closer field lines represent stronger field**

Answer 269

**Radial fields** have a **decreasing field strength** (Field lines increasing in separation) **Uniform fields** have a **constant field strength** (Field lines constant\ separation)

Answer 270

Over **small distances** When radial fields are approximately uniform And **g is approximately constant**

Answer 271

SUVATs need a **constant acceleration** Radial fields have a variable field strength and so a variable acceleration

Answer 272

An equipotential has **the same potential along that line** (So no work is done moving along the equipotential) They are **always perpendicular to field lines**

Answer 273

**Force** acting between two bodies is: 1. **Directly proportional to the product of their masses (F∝m₁m₂)** 2. **Inversely proportional to the square of their separation (F∝1/r²)**

Answer 274

The force acting per unit mass on an object in a gravitational field [NKg^-1] or [ms^-2]

Answer 275

The **mass** of the object **creating the field**

Answer 276

5000N also. An equal and opposite force from Newton's 3rd Law (Which has little effect on the Earth because it has so much more mass)

Answer 277

1. Calculate the field strength for each body in turn (ignoring the other one) 2. Calculate the difference between the field strengths (g is a vector)

Answer 278

The **work done** moving an object **from infinity** to that point in the field

Answer 279

* Gravitational **potential energy is 0 at infinite distance** * **And decreases inwards** as you move towards object creating field * (So must go negative)

Answer 280

The **work done per unit mass** moving an object **from infinity** to that point in a field

Answer 281

The **mass** of the object **creating the field**

Answer 282

Neither. **Potential energy (and potential) are scalar** quantities so are unaffected by the path ## Footnote **Both decrease by 1440MJ**

Answer 283

In the second stage the **mass of the satellite must be used** (Not the Earth's mass again)

Answer 284

Height is the distance above the surface So you **must add on the radius** of the planet/star/object

Answer 285

**Gravitational potential from both is negative** So they **combine** **To increase the magnitude** of the potential

Answer 286

When the **mass or masses are constant**

Answer 287

The **area under the curve is the change in potential energy** moving between the two separations

Answer 288

The **area under the curve is the change in potential** moving between the two separations

Answer 289

The **gradient of a tangent is the magnitude of the force** at that point

Answer 290

The **gradient of a tangent is the field strength** at that point

Answer 291

This part of the graph is linear as g ∝ r

Answer 292

* Use general equation for density (M/V) * With V as the volume of a sphere (4/3πr³) * Sub into general equation for field strength

Answer 293

1. Equate centripetal force to force due to gravity 2. Substitute in angular speed formula (from circular motion) 3. Rearrange

Answer 294

1. Equate centripetal force to force due to gravity 2. Rearrange

Answer 295

Mercury It is closest to Sun so **smallest r**

Answer 296

The **mass of the object creating the field**

Answer 297

1. Escape velocity only applies to objects without engines (that can't increase their KE) 2. Satellite isn't escaping the field (so doesn't need as much KE)

Answer 298

Substitute orbital velocity into equation for kinetic energy

Answer 299

Add the kinetic and potential energy together…

Answer 300

Both have orbital periods of 24 hours (the same as the Earth)

Answer 301

**Geostationary satellites orbit above the same point of the equator** and have an orbital period of 24 hours **Polar satellites orbit over the North and South pole** with an orbital period of much less (around 2 hours)

Answer 302

* Satellite television * Mobile Phone Communications * GPS

Answer 303

When electron and muon type particles are involve **each lepton number must be considered separately**

Answer 304

1. Charges moving in the field 2. Conductors with a current passing through 3. Other magnets 4. Magnetic materials

Answer 305

Field lines **always** act **North → South**

Answer 306

**Field is uniform** between the poles

Answer 307

Because it is **parallel to the field lines**

Answer 308

1. Looking at DC motors 2. Looking at charges moving in a magnetic field

Answer 309

First use trigonometry to calculate the **perpendicular component** of its **length**

Answer 310

The magnetic field pushes up on the conductor So the conductor pushes the magnets down (**Newton's 3rd Law**)

Answer 311

Increase the **torque** by:

Answer 312

**Switch connections** of the bars every 180° So **direct current is produced**

Answer 313

Force on each bar won't change So coil will reach **equilibrium in vertical** position And **won't continue spinning**

Answer 314

**Force** from magnetic field **perpendicular** to **velocity** of electron

Answer 315

**Current** acts **opposite** to the **velocity**

Answer 316

**Current** acts in the **same direction** as the **velocity**

Answer 317

**F=BIL on a conductor** in a magnetic field (with current) **F=BQv on a charge** in a magnetic field (moving)

Answer 318

**Equate** the magnetic and centripetal **forces**

Answer 319

**Greater the specific charge** → **Smaller r** (Bigger deflection)

Answer 320

0J because the **force and velocity vectors are perpendicular** So the charge does not increase its kinetic energy

Answer 321

Unless an ion's velocity = E/B, it will travel in a parabola and miss the gap

Answer 322

The ions have the **same velocity** (from the velocity selector) So **deflect by specific charge**

Answer 323

Alternating current → Electric Field between 'Dees' → Increases kinetic energy Magneti Field → Moves particle in circular path in ‘Dees’ → Containing particle

Answer 324

As the charge speeds up → Travels further in each Dee → So takes **same time**

Answer 325

**Note:** f is independent of v So the **frequency is constant**

Answer 326

Oscillations that have a **resultant transfer of energy** in one direction

Answer 327

**Mechanical waves require a medium** to oscillate through Electromagnetic waves don't require matter (oscillate through electric and magnetic fields)

Answer 328

Oscillations are **perpendicular** to the transfer of energy

Answer 329

Oscillations are **parallel** to the transfer of energy

Answer 330

1. Always **transverse** 2. Propagate with velocity of **3×10⁸ms^-1 through vacuum**

Answer 331

* Sound * P-waves (Earthquakes) * Water waves (beneath surface)

Answer 332

* E-M waves (Light, X-rays, UV etc) * Waves on string * S-waves (Earthquakes) * Water waves (surface)

Answer 333

Displacement → **Current distance** of a point from the equilibrium position Amplitude → **Maximum distance** a point reaches from equilibrium position

Answer 334

All points have the **same maximum displacement** from equilibrium position

Answer 335

Time taken for each particle to **complete one full oscillation** (Return to same position)

Answer 336

The number of complete **oscillations per second**

Answer 337

Distance between two adjacent corresponding points on a wave (Same displacement, no phase difference)

Answer 338

**360° ∼ 0°** **2****π****∼ 0****π**

Answer 339

**180°** **π** **∼ Antiphase**

Answer 340

**540° ∼ 180°** **3π** **∼** **π** **∼ antiphase**

Answer 341

**420° ∼ 60°** **14π/6** **∼** **π/3**

Answer 342

**Compressions** and **rarefactions**

Answer 343

**Only transverse waves can be polarised** (Sound is longitudinal)

Answer 344

1. Light vertically polarised through first grating 2. Vertically p[olarised light can't pass through horizontal grating 3. **Final intensity = 0**

Answer 345

1. Light vertically polarised through first grating (intensity halves) 2. Vertically polarised light passes through second grating 3. **Final intensity = ½**

Answer 346

1. When **sunlight reflects** off surfaces it is **polarised** 2. Sunglasses have filter to **block polarised light** 3. Only unpolarised light passes through

Answer 347

Ratio of speed of light in a vacuum : speed light passes through material (The greater n \> the more light slows down)

Answer 348

θ₂ \> θ₁ (Light speeds up and **bends away from normal**)

Answer 349

θ₂ \< θ₁ (Light speeds up and **bends towards normal**)

Answer 350

**Yes** It hasn't bent towards or away from normal **But it has slowed down**

Answer 351

**Frequency does not change** (But wavespeed and wavelength do)

Answer 352

Different wavelength refract by different amounts So light passing through a prism separates into wavelengths

Answer 353

In Snell's law **θ₁ is the angle between normal and incident ray**

Answer 354

1. **θ₁ \> θ_c** 2. **n₂ \< n₁**

Answer 355

Using basic geometry (angles in triangle add to 180°)

Answer 356

1. Information transmission faster 2. More information can be transmitted 3. Less energy loss (copper heats up)

Answer 357

1. Protects the core from scratches and spills 2. Stops data loss to adjacent fibres 3. Increases critical angle (reducing modal dispersion)

Answer 358

Different modes (angles) take different amount of time to propagate through an optical fibre Leads to **pulse broadening** Combatted by **making core narrow** and using cladding with low n **(increasing** **θ_c)**

Answer 359

**Different wavelengths** (colours) of light **refracted by different** amounts Leads to **pulse broadening** **Combatted using monochromatic light**

Answer 360

Form a **superposition** Displacements combined (added or subtracted) at each point

Answer 361

**Constructive interference** (Displacements combine)

Answer 362

**Destructive interference** (Displacements cancel)

Answer 363

1. Progressive wave reflects off a fixed point 2. Two progressive waves propagating in opposite directions (with same c,f,λ,A) 3. Waves overlap and interfere forming superposition

Answer 364

Nodes → Points of 0 amplitude Antinodes → Points of maximum amplitude

Answer 365

* All points on a progressive wave have same amplitude (Stationary waves have range) * Progressive waves resultant energy transfer (Stationary waves have 0 resulatant)

Answer 366

**Each loop = ½****λ**

Answer 367

1. Calculate the frequency of the 1^st harmonic 2. Multiply f₁ by n

Answer 368

A and B have **different maximum displacements**

Answer 369

0° → All points on same side of equilibrium are in phase

Answer 370

A and B → 180° → All points on oppsoite side of equilibrium are in anti-phase C and D → 180° A and C → 0° → All points on same side of equilibrium are in phase B and D → 0°

Answer 371

* Decrease tension (reduce mass) * Increase distance between end points * Use string with greater density (greater μ)

Answer 372

1. Sources must be **coherent** (same frequency, constant phase difference) 2. Sources must be **monochromatic** (one wavelength)

Answer 373

When their **path difference = n****λ** So **phase difference = 0°** **Maxima** forms

Answer 374

When their **path difference = (n+½)****λ** So **phase difference = 180° (∏ rad or antiphase)** **Minima** forms

Answer 375

When the wavelength is close to the size of the gap the wave passes through

Answer 376

**Large central maxima** **Intensity decreases exponentially** **Each maxima has half width of central**

Answer 377

1. Increase λ 2. Increase slit to screen distance D 3. Decrease slit separation s

Answer 378

**Intensity decreases linearly** **Width of maximas constant**

Answer 379

between adjacent slits **Path difference = 1****λ** So **phase difference = 0°**

Answer 380

between adjacent slits **Path difference = 3****λ** So **phase difference = 0°**

Answer 381

**n_max = d/****λ** **Round Down!!!**

Answer 382

1. **Like** charges **repel** 2. **Opposite** charges **attract**

Answer 383

**Electric field lines** shows **direction** of Force on **+ve charges** **(-ve charges** are **opposite)**

Answer 384

1. **Radial** fields have a **varying field strength** (weaker when further apart) 2. **Uniform** fields have a **constant field strength**

Answer 385

**Equipotentials always perpendicular** to field lines

Answer 386

1. Increase field strength 2. Increase magnitude of charge

Answer 387

Field lines always act… * **Away from +ve** * **Towards -ve**

Answer 388

**NOTE: Field lines never cross**

Answer 389

**Field strength is constant between parallel plates** (capacitor) ## Footnote **E₁= E₂ = E₃**

Answer 390

**Electric potential linearly increases between parallel plates** (capacitor)

Answer 391

**Force per unit charge** acting on a small **positive charge**

Answer 392

F=Eq → 5x6 = **30N**

Answer 393

**Electric field strength ≠ acceleration**

Answer 394

**Treat it as a point charge**

Answer 395

**E=0 everywhere!!!**

Answer 396

For **parallel plates calculate E first if possible**

Answer 397

1. Work out **field strength from each** 2. Label vectors 3. **Add or subtract** field strengths

Answer 398

Yes! Field strength constant → Acceleration constant

Answer 399

**E_p = 0 at** **∞** **Increases as charge moves closer**

Answer 400

**E_p = 0 at** **∞** **Decreases as charge moves closer**

Answer 401

**E_p = 0 at** **∞** **Increases as charge moves closer**

Answer 402

**E_p = 0 at** **∞** **Decreases as charge moves closer**

Answer 403

**Work done per coulomb** moving **positive charge** from **infinity to that point**

Answer 404

Equipotentials show the change in potential of a +ve charge If +ve charge → decreases If -ve charge → increases

Answer 405

**Q is the charge creating** the field **q is the charge moving** in the field

Answer 406

Electric potential is scalar But they are **opposite → must be subtracted**

Answer 407

**Same as field strength** graph

Answer 408

1. Radial field over a short distance 2. Field between 2 parallel plates

Answer 409

**Charge stored per unit Volt [F]**

Answer 410

**Gradient → Capacitance** **Area → Work done** (Energy Stored)

Answer 411

**C = capacitance →** not the charge!!!

Answer 412

1. **Increase the area** of the plates 2. **Decrease** the plate **separation** 3. Place **dielectric** between plates

Answer 413

The capacitor stores **5x more charge with the dielectric** between the plates!

Answer 414

1. Dielectric contains **polarised molecules** 2. They **align with the field** between the plates 3. Bigger negative charge **attracts more electrons** onto negative plate 4. Repels more electrons away from positive plate 5. **V same** but **Q has increased**

Answer 415

1. Polarised molecules removed 2. **Some electrons leave negative** plate 3. **Attracts more electrons to positive** plate 4. **Q has decreased** but **V same** 5. **C decreases (C=Q/V)**

Answer 416

1. Polarised molecules removed 2. But charge is trapped on plates 3. **Same Q** but with **lower C** 4. **V increases (V=Q/C)**

Answer 417

1. **Electrons flow** from the negative terminal of the battery 2. **To the connected parallel plate** (right plate) 3. **Electrons are repelled** from the opposite plate (left) 4. And attracted **to the positive terminal** of the battery 5. Charge across Parallel plates

Answer 418

1. **Electrons flow** from the negative plate (right) 2. Through the resistor 3. **To the other plate** (left) 4. Decreasing charge difference across plates

Answer 419

Time constant is how long it takes for a capacitor to… 1. **Charge to 63%** of max charge (0.63Q₀) 2. **Discharge 63%** of Q₀ (down to 0.37Q₀)

Answer 420

1. The **resistance of the components** in the circuit (Capacitor R=0) 2. **Capacitance** **of the capacitor**

Answer 421

Read off time when **charge (or current or voltage)** has **decreased to 37% initial**

Answer 422

Read off time when **charge (or current or voltage)** has **increased to 63% final**

Answer 423

1. Potential difference across capacitor drives large current through resistor 2. Charge across plates decreases 3. Potential difference across the plates decreases 4. Current gets smaller and smaller

Answer 424

1. Battery drives current round circuit 2. Charge build up on capacitor plates 3. Potential difference builds up across plates 4. Difference in PD between battery and capacitor gets less 5. So smaller push on electrons 6. Smaller current

Answer 425

80% is the decrease in charge (∆Q) So it **discharges to 20% of initial** Q=0.2Q₀

Answer 426

Use a **variable resistor** Decreasing resistance To keep **charging/discharging current constant**

Answer 427

Current → Constant Voltage and Charge → Linear

Answer 428

Current → Constant Voltage and Charge → Linear

Answer 429

**Set t=RC**

Answer 430

Capacitor is **discharging at a constant rate** So **current is constant**

Answer 431

**NOTE: V_R+V_C=V₀**

Answer 432

**NOTE: V_R+V_C=V₀**

Answer 433

**Current** at that instant

Answer 434

**Current** at that instant

Answer 435

**Charge lost** in that region

Answer 436

**Charge gained** in that region

Answer 437

Magnetic flux density x Perpendicular area

Answer 438

Must take **component of field perpendicular** to surface (Or component parallel to normal of surface)

Answer 439

**Flux doesn't change** But **flux linkage increases**

Answer 440

Must take **component of field perpendicular** to coil (Or component parallel to normal of coil)

Answer 441

**Moving the magnet** in and out of the coil Causes a **change in flux linkage** (Faraday's Law)

Answer 442

Emf **only induced if the flux linkage is changing** | (Faraday's Law)

Answer 443

Current acts to create a magnetic field **opposing the increase in flux linkage** (Tries to keep magnet from entering) Due to **Lenz's law**

Answer 444

Current acts to create a magnetic field **opposing the decrease in flux linkage** (Tries to keep magnet from leaving) Due to **Lenz' law**

Answer 445

The **rate of change of flux linkage is greater** | (Faraday's law)

Answer 446

The magnitude of the **emf is proportional to the rate of change of flux linkage**

Answer 447

The direction of an induced **emf tends to produce a current which opposes the** **change** causing it

Answer 448

The magnetic field produced attracts the magnet Increasing its kinetic energy Energy has been created out of nothing!!! (Against Lenz' law)

Answer 449

A current in a coil produces a magnetic field as shown

Answer 450

**Flux linkage becomes negative** when coil flips!!!

Answer 451

(From Faraday's law)

Answer 452

**emf = -ve gradient**

Answer 453

**emf = -ve gradient**

Answer 454

For **generators**!!!

Answer 455

When **change in flux linkage is max** | (When flux linkage = 0)

Answer 456

When **change in flux linkage is 0** | (When flux linkage = max)

Answer 457

**Increase any of the terms** in the equation:

Answer 458

**Generator: Kinetic energy -\> Electrical** energy (Motor: Electrical energy -\> Kinetic energy) **Generator: Slip rings** keep each side of coil connected to same side of circuit (Motor: Commutator ring switch polarity every half cycle)

Answer 459

**Currents produced in a conductor by magnetic fields** (Lenz' law in conductors)

Answer 460

1. Magnet in freefall 2. Plastic not a conductor so no eddy currents (still in freefall) 3. Copper pipe incomplete so can't create eddy currents (still in freefall) 4. Eddy current reduce acceleration

Answer 461

1. Flux linkage decreasing above -\> current creates attracting field upwards 2. Flux linkage increasing below -\> current creates repelling field upwards

Answer 462

1. Part of disk leaving field -\> current creates attraction to electromagnet 2. Part of disk entering field -\> current creates repulsion to electromagnet

Answer 463

To **hold a car stationary** on a slope | (no change in flux linkage)

Answer 464

The **equivalent DC voltage that would supply the same average power**

Answer 465

The **equivalent DC current that would supply the same average power**

Answer 466

When using electricity formulas **must use rms values for voltage** (and current)

Answer 467

1. AC current flows through primary coil 2. Magnetic field flows through secondary coil 3. Changing flux linkage in secondary coil larger 4. Greater emf induced (so bigger voltage)

Answer 468

1. AC current flows through primary coil 2. Magnetic field flows through secondary coil 3. Changing flux linkage in secondary coil smaller 4. Smaller emf induced (so smaller voltage)

Answer 469

**If supply is DC** **Flux linkage** in secondary coil **doesn't change** So emf isn't induced (Faraday's law)

Answer 470

This **equation always works (no matter what efficiency)**

Answer 471

(The **voltages and currents must be rms** values)

Answer 472

1. Large Eddy currents in magnet (P=I²R) 2. Large currents in primary and secondary coils 3. Hysteresis losses (magnet's resistance to change in flux linkage) 4. Flux losses (not all flux passing through secondary coil)

Answer 473

1. **Laminate** the core 2. Use **wire with** **low resistance** 3. Use **soft iron core** for magnet 4. **Wind primary coil over secondary** **coil**

Answer 474

**Smaller currents = smaller energy losses** to thermal | (P=I²R)

Answer 475

1. **Most** alpha particles passed through gold leaf **undeflected** 2. **Some** were **slightly deflected** 3. A tiny proportion (**1 in 8000) reflected**

Answer 476

1. Atom is **mostly empty space** 2. Centre of atom is **small, dense and positively charged (nucleus)**

Answer 477

* *Alpha most ionising** * *Beta medium ionising** * *Gamma least ionising**

Answer 478

* *Gamma most penetrating** * *Beta medium penetrating** * *Alpha least penetrating**

Answer 479

``` Alpha = 3-7cm Beta = 0.2-3m Gamma = Very long distance ```

Answer 480

1. **Radiation ionises gas** in tube 2. Negative **ions attracted** to metal rod 3. Positive ions attracted to casing 4. Small **current generated** in circuit

Answer 481

If detector count too low -\> metal too thick -\> Rollers move closer together If detector count too high -\> metal too thin -\> Rollers move apart Alpha won't be detected

Answer 482

* *Alpha = Paper** * *Beta = Aluminum** * *Gamma = Lead or several meters of concrete**

Answer 483

**Alpha radiation ionizes** air between detector **Ionized air causes current** to flow **Smoke blocks ionization** of air Current stops Alarm sounds

Answer 484

9x smaller **Gamma radiation follows inverse square law**

Answer 485

1. **Minimise** exposure **time** 2. **Maximize distance** from source 3. Store in shielded containers 4. Don't consume food or drink near source

Answer 486

**Medical tracer with short half life** injected Tumors absorb radionuclides and emit gamma Gamma detected outside body

Answer 487

**Gamma radiation focused on tumor** High energy breaks apart tumor Low levels through other tissue

Answer 488

1. An **incorrect balance of protons and neutrons** (off line of stability) 2. **Too many nucleons** 3. **Nucleus in excited state**

Answer 489

**Proton** captures inner shell electron and **becomes neutron**

Answer 490

**X-ray** → electron de-excites to fill inner shell **γ** → Nucleus reorders and de-excites

Answer 491

KE at distance → PE closest Use to get rough size of nucleus

Answer 492

**Average radius of each nucleon**

Answer 493

**Atom is mostly empty space**

Answer 494

Graph plotted First minima used to calculate diameter (Don't need to know equation)

Answer 495

**Alpha Recoil** * Closest approach so only an estimate * Recoil of nucleus not considered * Effect of strong force not known **Electron Scattering:** * Not affected by strong force (leptons) * Electron **λ_db tunable**

Answer 496

The **probability** that an unstable isotope **decays in one second**

Answer 497

The **total number** of unstable isotopes that **decay after one second**

Answer 498

1. The **decay constant** **λ** 2. The **number if unstable isotopes N**

Answer 499

Time taken for either… 1. Activity of sample to halve 2. **Number of unstable isotopes remaining to halve**

Answer 500

Set **N as 0.5N₀**

Answer 501

Find **multiple T_½ and compare**

Answer 502

**Activity and time must be the same units**

Answer 503

r₀ → **average radius of nucleon**

Answer 504

where r₀ → **average radius of nucleon**

Answer 505

Dealing with **fusion or fission** (Calculating mass defects, binding energies or mass difference)

Answer 506

Mass lost when nucleons (protons and neutrons) **come together to form nucleus**

Answer 507

**Energy released** **when nucleons** (protons and neutrons) **come together** to form nucleus

Answer 508

Mass of **1/12 of a carbon-12** atom (1.661x10^-27kg)

Answer 509

**Multiply by 931.5MeV**

Answer 510

**Use E=mc²**

Answer 511

Energy only released if **binding energy per nucleon increases**

Answer 512

**Long-lived excited state** of nucleus Eventually it de-excites emitting **γ**

Answer 513

**2****β^- and 3γ**

Answer 514

Heavy **nucleus splits into two** lighter nuclei **releasing energy and neutrons**

Answer 515

**U-235, U-238**

Answer 516

Calculate the **mass difference (****∆****m_diff)**

Answer 517

**If mass difference is positive** reaction is possible

Answer 518

1. **Fuel rods** - U-235 2. **Control rods** - Boron 3. **Moderator** - water or graphite 4. **Coolant** - CO₂ or water

Answer 519

**Reduce neutrons' speeds** to thermal speeds (More likely to be absorbed by U-235)

Answer 520

**Absorb some neutrons** Stop chain reaction occurring

Answer 521

1. Reaction happens inside **thick walled concrete** vessel 2. **Control rods fully inserted** if meltdown starts 3. **Reactor flooded with water** to remove thermal energy if meltdown starts

Answer 522

1. Removed remotely from reactor 2. Stored in **cooling ponds** for up to 1 year 3. **Vitrified** by mixing with molten glass 4. Sealed in **barrels** 5. Stored in mountains or **deep underground**

Answer 523

**Two lighter nuclei are combined** to form one heavier nuclei and **release energy**

Answer 524

Requires **incredibly high temperatures and pressures** 1. To **ionise** the isotopes 2. To bring isotopes close enough to **overcome electromagnetic repulsion**

Answer 525

Close enough for the **strong force to be larger than electromagnetic** ## Footnote **(\<1fm)**

Answer 526

Deuterium → H-2 Tritium → H-3

Answer 527

**Transfer heat** from fuel rods to the water that spins the turbines

Answer 528

The magnetic field that applies a **force of 1N to a 1 metre conductor** with a **1A current** flowing **perpendicular to the field** (B=F/IL)

Answer 529

N → neutron number Z → Proton Number

Answer 530

N → neutron number Z → Proton Number

Answer 531

N → neutron number Z → Proton Number

Mega Deck Flashcards

(643 cards)