Math/Physics Flashcards

Question

What is the speed of sound in air at 20C?

Answer 1

Direct current (DC): the charge flows in one direction only (like batteries) Alternating Current (AC): the flow changes direction periodically (like the current supplied over long distances to homes and other buildings)

Answer 2

- The rate at which energy is dissipated by a resistor is the power of the resistor P= IV= I²R=V₂/R I: the current through the resistor V: the voltage drop across the resistor R: resistance of the resistor Note: the above equations can be derived by substitution using Ohm's Law (V=IR)

Answer 3

Molecular level: temperature is proportional to the average kinetic energy of the particles that make up the substance At the macroscopic level, it is the difference in temperature between two objects that determines the direction of heat flow

Answer 4

- The number of wavelengths passing a fixed point per second - Measured in hertz (Hz) - Symbol: f

Answer 5

- A type of radioactive decay where the emission of an α-particle α-particle: ⁴₂He

Answer 6

F_c= mv²/r

Answer 7

The ratio of the magnitude of a charge's electrical potential energy to the magnitude of the charge itself V = U/q V: electrical potential measured in volts Can also say: V = kQ/r - Note: Do not confuse this with electrical potential energy

Answer 8

- Occurs when forces are applied against anbject in such a way as to cause the object to rotate around a fixed pivot pound, known as the fulcrum

Answer 9

Efficiency = W_out/W_in= (load x load distance)/ (effort x effort distance - Often expressed as a percentage by multiplying the efficiency ratio by 100%

Answer 10

Offers a direct relationship between the work done by all the forces acting on an object and the change in kinetic energy of the object W_net= ΔK = K_f-K_i

Answer 11

- Liquid in a container creates a concave meniscus, a curved surface in which the liquid "crawls" up the side of the container a small amount, because the adhesive forces are greater than the cohesive forces - Mercury in a container will create a convex (backwards) meniscus, as the cohesive forces are greater than the adhesive forces

Answer 12

**F_B= qvbsinθ** q: the charge v: the magnitude of its velocity B: the magnitude of the magnetic field θ: the smallest angle between the vector **v** and the mangetic field vector **B**

Answer 13

1Å = 10^-10m

Answer 14

- Have unpaired electrons, so these atoms have a net magnetic dipole moment, but the atoms in these materials are susually randomly oriented so that material itself creates no net magnetic field - Will become weakly magnetized in the presence of an external magnetic field, aligning magnetic dipoles of the material with the external field - Upon removal from the external field, the thermal energy of the individual atoms will cause the individual magnetic dipoles to reorient randomly - Examples: aluminum, copper, and gold

Answer 15

Phases changes occur at constant temperature and the temperature will not begin to change until all of the substacnce has been converted from one phase into another Equation: q=mL q: amount of heat gained or lost from material m: mass of the substance L: heat of taransformation - Cannot use q=mcΔT, because there is not change in temperature

Answer 16

A blurring at the periphery of an image as a result of inadeuqate reflection of parallel beats at the edge of a mirror or inadequate refraction of parallel beams at the edge of a lens - This creates an area of multiple images with very slightly distances at the edge of the image, which can be blurry

Answer 17

**First Law**: a body either at rest or in motion with constant velocity with remain that way unless a net force acts upon it; also known as _inertia_ Equation: F_net= ma=0 **Second Law**: An object of mass m will accelerate when the vector sum of the forces results in some nonzero resultant force vector Equation: F_net=ma **Third Law**: To every action, there is always an opposite but equal reaction Equation: F_AB= -F_AB

Answer 18

- If i has a positive value ( i \> 0 ), then it is a real image, which implies that the image is in front of the mirror - If i has a negative value ( i \< 0 ), then it is a virtual image, which implies that the image is behind the mirror

Answer 19

- The rate at which energy is transferred from one system to another P= W/t= ΔE/t P: power W: work t: time SI Unit: Watt (W) = J/s

Answer 20

- A type of radio-decay in which a β-particle is emitted β-particle: is an electron (given the symbol e^- or β^-) - During β^- decay, a neutron is converted into a proton and a β^-particle emitted - Since protons and neutrons have basically the same mass, the mass number does not change, but the atomic number goes up by 1

Answer 21

- As light travels from a medium with a higher index of refrection to a medium with a lower index of refraction, the refracted angle is larger than the incident angle (θ₂ \> θ₁) - As the incident angle is increased, the refracted angle also increases - At some point, this will increase to the critical angle (θ_C), for which θ₂equals 90 degrees - Total internal reflection occurs when all the light incident on a boundary is reflected back into the original materal, and results when any angle of incidence is greater than θ_C

Answer 22

- Characterized the ability to flow and conform to the shapes of their containers

Answer 23

**n= n₀e ^-λt** n: the number of radioactive nulcei that have not yet decayed in the sample n₀: the number of undecayed nuclei at time 0 λ: decay constant t: the time passed since time 0

Answer 24

For capacitors in series, **1/C_s= 1/C₁ + 1/C₂ +1/C₃ + 1/C₄...** For capacitors in parallel, **C_s = C₁+C₂+C₃+C₄...**

Answer 25

λ = 0.693/T_1/2 λ: decay costant

Answer 26

- Waves in which the particles of the wave oscillate parallel to the direction of propagatoin - _Sound waves_ are the prime example of longitudinal waves (Image A)

Answer 27

v= fλ v: speed of the wave f: frequency λ: wavelength

Answer 28

- The distance from one crest to the next crest (or one trough to the next) Symbol: λ

Answer 29

- The average rate of energy transfer per area across a surface that is perpendicular to the wave **I=P/A** P: power A: area

Answer 30

τ = r x F= rFsin θ r: the length of the lever arm F: magnitude of force θ: the angle between the lever arm and force vectors

Answer 31

- The amount of charge passing through a conductor per unit time I = Q/Δt Units: Ampère (1A= 1C/s)

Answer 32

**λ = 2L/n** n: positive, non-zero integer (called the harmonic) L: length of the string **f= nv/2L** f: frequency v: wave speed

Answer 33

- The process by which a quantity of energy is tranferred between two object as a result in a difference in temperature

Answer 34

- If a string is fixed at one end and is moved up and down, a wave will form and travel, or propogate, toward the fixed end - Called a traveling wave, becuase the wave moves - If the free end of the string is continuously moved up and down, there will be two waves: the original wave moving down the string toward the fixed end and the reflex wave moving away from the fixed end; the waves will interefere with each other

Answer 35

- Have their own battery of known voltage and then function as ammerteres through another point in the circuit - Use Ohm's law to calculate resistance - Needs the circuit to be off

Answer 36

Thermal equilibrium

Answer 37

- Turbulent flow can arise when the spped of the fluid exceeds a certain critical speed v_c= N_Rη/ρD N_R: dimensionless constant called Reynolds number η: viscosity of the fluid ρ: density of the fluid D: diameter of the tube

Answer 38

- Used to measure the current at some point within a circuit - Inserted in series where the current is being measured and sue the magnetic properties of the current-carrying wire to cause a visisble needle to vmove or a calibrated display of the current - If the curent is particualrly high, this will overwhlem the ammeter, and a special low resistance shunt is sued in parallel with the ammeeter to allow a reading - must have extremely low resistance so they do not change circut mathematics when inserted

Answer 39

- A change in an objects position in space - Vector quantity - The displacement vector connects (in a straight line) the objects initial position and its final position - Displacement does not account for the actual pathway taken between the initial and final positions-- only the net change in position from initial to final

Answer 40

- Objects in thermal contact and not in thermal cequilibrium will exchange heat energy such that the object with a higher temperature will give off heat energy to the ojbect with a lower temperature until both objects have the same temperature at thermal equilibrium

Answer 41

- Surface tension causes a liquid to form a thin but strong layer at the liquid's surface - Results from **cohesion**, which is the attractive force that a molecule of liquid feels toward other molecules of the same liquid

Answer 42

**Metallic conductivity** - As seen in solid metals and the molten form of some salts - Materials which allow free flow of electric charge within them - Metal atoms can easily lose one or more of their outer electrons, which are then free to move around in the larger collection of metal atoms **Electrolytic conductivity:** - Seen in solutions - Depends on the strenght of a solution (distilled deionized water is an insulator, but salt water is a conductor) - Since there is a direct relationship, you can use conductivity to determine concentration, but note that conductivity is always lower in non-ionic solutions than ionic solutions

Answer 43

The rate of change of velocity that an object experiences as a result of some applied force - Deceleration: acceleration in the opposite direction as the initial velocity

Answer 44

1. Start by pointing your thumb in the direction of vector A 2. Extend your fingers in the direction of vector B. You may need to rotate your wrist to get the correct configuration of thumb and fingers. 3. Your palm establishes the plane between the two vectors. The director your palm points is the direction of the resultant C.

Answer 45

The maximum magnitude of displacement of a wave, from the equilibrium Symbol: A

Answer 46

1. Resolve the vectors to be added into their x- and y- components 2. Add the x-components to get the x-component of the resultant and the y-components to get the y-component of the resultant 3. Find the magnitude of the resultant by using the pythagorean theorum 4. Find the direction of the resultant by using the relationship θ = tan^-1 (R_y/R_x)

Answer 47

**v = √(B/ρ)** v: velocity of sound B: bulk modulus, a measure of the medium’s resistance to compression (B increases from gas to liquid to solid) ρ: the density of the medium

Answer 48

- Magnitude is measured as the rate of change of displacement in a given unit of time - SI units: m/s - Vector quantity

Answer 49

- States that when waves interact with each other, the displacement of the resultant wave at any point is the sum of the displacements of the two interacting waves - The principle which explains constructive, destructive and partially constructive/destruction interference

Answer 50

- A type of radio-decay in which a γ-ray is emitted γ-ray: high energy photons - They carry no charge and simply lower the enrgy of the parent nucleus without changing the mass number or atomic number

Answer 51

- When a vector is multiplied by a scalar, its magnitude will change but the direction will either be parallel or antiparallel to the original direction B=nA, where A is the original vector, n is the scalar quantity and be is the new vector; the direction of B depends on the sign on n, if positive, then parallel, if negative, then antiparallel

Answer 52

- The passing of a shock wave - As a shock wave passes, there is a very high pressure, followed by a very low pressure, which creates a sonic boom - A sonic boom can be heard any time that an object traveling at or faster than the speed of sound passes a detector

Answer 53

ΔU = Q-W ΔU: change in the system's internal energy Q: energy transferred into the system as heat W: work done by the system Sign convention, see image

Answer 54

- An expression of conservation of energy for a flowing fluid; states that the sum of the static pressure and dynamic pressure will be constant between any two points in a cloed system P₁ +1/2 ρv₁² + ρgh₁ = P₂ +1/2 ρv₂² + ρgh₂ P: absolute pressure of fluid ρ: density of fluid v: linear speed of fluid h: height of fluid

Answer 55

Power: the strength of the lens P = 1/f f: focal length Units: diopters

Answer 56

- The number of seconds per cycle (the opposite of frequency) T= 1/f

Answer 57

F_g = Gm₁m₂/r² Where G is the universal gravitational constant : 6.67x 10^-11N x m²/kg² R: the distance between the centers of mass of the two objects

Answer 58

- Plane mirrors- being flat reflective surfaces, cause neither diverge nor converge of reflected rays - Since convergence of the rays cannot happen, real images cannot be produced - Thus, all images are produced by a plane mirror are virtual

Answer 59

ΔL = αLΔT ΔL: change in length α: the coefficient of linear expansion L: original length ΔT: change in temperature

Answer 60

Cohesion: the attractive force that a molecule of liquid feels toward other molecules of the same liquid Adhesion: the attractive force that a molecule feels toward the molecules of another substance

Answer 61

- Will not easily distribute a charge over its surface and will not transfer that charge to another neutral object very well- especially not to another insulator - Most nonmetals are insulators

Answer 62

When waves are perfectly out of phase, the displacement always counteract each other and the amplitude of the resultant wave is the difference between the amplitudes of the interacting waves

Answer 63

FB= ILBsinθ I: the current L: length of the wire in the field B: the magnitude of the magnetic field θ: the smallest angle between the vector L and the mangetic field vector B

Answer 64

**Vector**: numbers that have magnitude and direction - Includes: displacement, velocity, acceleration and force **Scalar**: numbers that have magnitude only and no direction - Incldues: distance, speed , energy, pressure and mass

Answer 65

- Given a charge, a conductor will distribute the charge approximately evenly upon its surface - Able to transfer and transport charges - Often coceptualized as nuclei surrounded by a sea of free electrons that are able to move rapidly throughout the material and are only loosely associated with positive charges - Generally metals but can also include some ioninc solutions

Answer 66

m = - i / o i: distance between the image and the mirror o: distance between the object and the mirror - If m= positive, then the image is upright - If m= negative, then the image is inverted - If |m| \< 1, then the image is smaller than the object (reduced) - If |m| \> 1, then the image is greater than the object (enlarged)

Answer 67

**n₁ sin θ₁ = n₂ sin θ₂** - n₁ and θ₁ refer to the medium from which the light is coming - n₂ and θ₂ refer to the medium into which the light is entering - If n₂\>n₁, light bends toward the normal - If n₂\<n₁, light bends away from the normal

Answer 68

- Exists only when the vector sum of all the forces acting on an object is zero - This is called the first condition of of equilibrium - Since the vector sum forces are equal to 0, it will not acclerate and will have constant velocity (constant speed and constant direction)

Answer 69

- Since water is incompressible, the force on a piston is pushed down, it exerts a force which displaces a given volume of water; this same volume must be displaced on the opposite side, which creates a pressure and thus a force upwards P= F₁/A₁ = F₂/A₂

Answer 70

- When light travels through a homogenous medium, it travels in a straight line

Answer 71

The rate of flow through a given pipe or confined space, given laminar flow

Answer 72

- Uses the bending of light rays to create a model of molecules - X-ray diffraction is often combined with protein crystallography during protein analysis - Dark and light fringes do not take on a linear appear, but rather a complex two dimensional image

Answer 73

1eV= 1.6 x 10^-19J - This is the amount of energy gained by an electron accelerating through a potential difference of one volt

Answer 74

U= 1/2 CV² - C: Capacitance V: voltage - (The function of a capacitor is akin to a dam, the purpose of which is to store gravitational potential enerrgy by holding back a mass of water at a given height)

Answer 75

F_g= mg F_g: weight of the object m: mass g: gravity

Answer 76

- A measure of energy J = (kg⋅m²)/s²

Answer 77

e = 1.60 x 10^-19C proton: +1.60 x 10^-19C electron: -1.60 x 10^-19C

Answer 78

v = v_o + at x = v_ot +1/2at² v² = v_o² +2ax x = v_avgt

Answer 79

Static friction: exists between a stationary object and the surface upon which it rests 0 ≤ f_s≤ μ_sN μ_s: coefficient of static friction Kinetic friction: exists between a sliding object and the surface over which the object slides f_k = μ_kN μ_k: coefficient of kinetic friction

Answer 80

- The rate of actual distance traveled in a given unit of time

Answer 81

- A logarithmic scale used for measuring sound intensity β= 10 log I/I₀ I: intensity of the sound wave I₀: threshold of hearing (1 x 10^-12W/m²)

Answer 82

- Nearsighted or myopia (can see near objects clearly) need diverging lenses - Farsighted or hyperopia (can see distant objects clearly) need convering lenses

Answer 83

Describes the relationship between the variables in a real lens; i.e. a lens that does not have negligible thickness **1/f = (n-1) (1/r₁ - 1/r₂)** Note: for almost all MCAT questions, lenses will have negligible thickness and this equation is not application

Answer 84

- If the incident photon is above the threshold frequency of the metal, the photon will have enough energy to eject a single electron, and any exess energy will be convereted to kinetic energy in the ejected electron K_max = hf - W W: work function of the metal in question _Work function_: the minimum energy required to eject an electron and is related to the threshold frequency of the metal W=hf_T Note: the exact kinetic energy can be anywhere between 0 and K_max; K_max is only achieved when all possible energy from the photn is transferred to the ejected electron

Answer 85

- Lenses in contact are a series of lenses with negligible distances between them, behave as a single lens with equivalent focal length 1/f = 1/f₁ +1/f₂ +1/f₃ +1/f₄...1/f_n Because power is the reciprocal of focal length, P = P₁ + P₂ + P₃ + P₄... P_n

Answer 86

- As a sound wave emanates outward for their source, it is though the waves are pushing against the interior wall of the ever-expanding balloon - Because the surface area of the sphere increases as a function of the square of the radius (A=πr²), sound ways transmit their power over larger and larger areas the further from the source **- Intensity is inversely proportional to the square of the distance from the source**

Answer 87

System: a portion of the universe that we are interested in observing or manipulating; the rest is the surroundings - **Isolated systems**: are not capable of exchanging energy or matter with their surrounds; thus, the total change in internal energy must be zero Example: bomb calorimeter - **Closed system**: Capable of exchanging energy, but not matter, with the surroundings Example: gases in vessels with movable pistons - **Open systems**: can exchange matter and energy

Answer 88

- Refers to an ideal absorber of all wavelengths of light, which would appear completely black if it were at a lower temperature than its surroundings

Answer 89

Softest sound: 1 x 10^-12 W/m² Pain: 10 W/m² Burst eardrum: 1 x 10⁴ W/m²

Answer 90

- When light travel through a medium, different wavelengths travel at different speeds; the index of refraction of a medium affects the wavelength of light passing through the medium because of n=c/v - Disperseion: When various wavelengths of light separate from each other Example: white light through a prism

Answer 91

**Straight wire:** B = μ₀I/ 2πr - This is the magntidue of the magnetic field at a perpendicular distance, r, from the wire **Circular wire:** B = μ₀I/ 2πr - This is the magnitude of of the magnetic field at the center of the circular loop μ₀: permeability of free space

Answer 92

The opposition within any material to the movement and flow of charge - Materials that offer almost no resistace are called conductors - Materials that offer very high resistance are called insulators

Answer 93

- When small nuclei combine to form a larger nucleus - Example: the sun fuses four hydrogen nuclei to make one helium nucleus

Answer 94

- Our perception of the frequency of sound - Lower frequency sounds have lower pitch; higher frequency sounds have higher pitch

Answer 95

- By calculating the area enclosed by the corresponding Pressure-Volume curve - W=PΔV In an isovolumetric process, the ΔV=0, so the change work done is 0 In an isobaric process, then W=PΔV

Answer 96

- Air resistance, opposes the motion of an object; its value increases as the speed of an object increases - Therefore, an object in free fall wil experience a growing drag force as the magnitude of its velocity increases - Eventually this drag force will be euqal in magnitude to the weight of the object and the object will fall with constant velocity (Newton's 1st Law) - This is the **terminal velocity**

Answer 97

- Perpendicular: both - Shear forces: solids

Answer 98

- The lowest frequency (longest wavelength) of a standing wave that can be supported in a given length of string - 1st harmonic (i.e. n= 1)

Answer 99

- Any moving charge creates a magnetic field - May be set up by the movement of individual charges, like electrons moving through space; by the mass movement of chargein the form a current through an copper wire, or by a permanent magnet Unit: Tesla (1 N x s/ M x C) Note: Teslas are large units, so 1 Tesla = 10⁴ Gauss

Answer 100

The flow of positiove charge (even though only negative charges are actually moving)

Answer 101

**Resistivity**: how good of a conductor a material is, intrinsically - ρ; unit: Ohm-meter (Ω-meter) **Length**: the longer something is, the further the electron has to pass through; if length doubles, resistance doubles - L **Cross-sectional area**: an increase in cross-sectional areea increases the number of pathways through a resistor (conduction pathways); the wide the resistor, the more current that can flow (think of a river) - A **Temperature**: most conductors have greater esistance at higher temperatures due to increase thermal ossicillation of the atoms in the conductive material, which produces a greater resistance to flow **R= ρL/A**

Answer 102

- Imaginary lines that represent how a **positive** test charge would move in the presence of a source charge

Answer 103

- When both ends of a string are fixed and traveling waves are excited in the string, certain wave frequenceies will cause interference between the traveling wave and its reflected wave such that they will form a waveform that appears to be stationary - The only apparent movmeent of the string is fluctuation of amplitude of fixed points along the length of the string - Nodes: points in the wave that remain at rest (where amplitude is constantly zero) - Antinodes: points midway between the nodes which fluctuate with maximum amplitude

Answer 104

States that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere Example: if one were to squeeze a milk container, the applied pressure would be transmitted through the entire volume of the milk

Answer 105

- When there are non-conservative forces, such as friction, air resistance, or viscous drag (a resistance created by fluid viscosity) acting on an object - W_{nonconservative}= ΔE= ΔU + ΔK - The work done by non-conservative forces will be exactly equal to the amount of energy "lost" from the system (it is actually just transformed into antoerh for of energy that is not accounted for in mechanical energy)

Answer 106

- **Solid to Liquid**: fusion or melting - **Liquid to Solid**: freezing or solidifcation - **Liquid to gas**: boiling, evaporation, or vaporization - **Gas to liquid**: condensation - **Solid to gas**: sublimation - **Gas to solid**: deposition

Answer 107

- The amount of energy that is released when nucleons (protons and neutrons bind together) - The more binding energy per nucleon released, the more stable the nucleus - The bound system is at a lower energy level than the unbound constituents, and this difference in erngy must be radiated away in the form of heat, light or other electromagnetic radion before the mass defect becomes apparent

Answer 108

- Sounds produced by objects which vibrate at multiple natural frequencies (a fundamental pitch and multiple overtones) that are related to each other by whole number ratios

Answer 109

- The capacitance of the parallel plate capacitor is dependent upon the geometry of the two conduction surfaces; for the simple case of the parallel plate capacitor, the capacitance is given by: C= ε₀(A/d) ε₀: permitivity of free space (8.85 x 10^-12F/m) A: area of overlap of the two plates d: separation of the two plates

Answer 110

ΔV = βVΔT ΔV: change in volume β: the coefficient of linear expansion V: original length ΔT: change in temperature Note: that the coefficient of volumetric expansion is equal to 3 times the coefficient of linear expansion for the same material (β=3α)

Answer 111

The difference in the absolute pressure inside a structure (like a tire) compared to the atmospheric pressure outside; in other words, the amount of pressure in a closed space above and beyond atmospheric pressure P_gauge = P - P_atm = (Po + ρgz) - P_atm

Answer 112

W= F⋅ d = Fd cos θ W: Work F: the magnitude of the force applied d: the magnitude of the displacement through which the force is applied

Answer 113

- The ratio of the magnitude of the charged stored on one plate to the potential difference (coltage) across the capacitor - Therefore, if a voltage V is applied acorss the plates of a capacitor and a charge Q collections on it (with +Q on the postive plate and -Q ont he negative plate), then... **C: Q/V** C: capacitance Q: charge V: voltage Units: Farad (1F= 1C/V)

Answer 114

- For magnitude: A x B = |A| |B| sin θ - To determine the direction, use the right hand rule

Answer 115

Fow rate: the volume per unit time; is constant for a closed system and is independent of cross-sectional area Linear speed: a measure of the linear displacement of fluid particles ina given amount of time; the product of linear speed (v) and cross sectional area (A) provide flow rate - Does change with cross-sectional area Q=v₁A₁=v₂A₂

Answer 116

F_{g, parallel} = mg sin θ F_{g, perpendicular} = mg cos θ

Answer 117

v_avg= Δx/Δt

Answer 118

- Certipetal force, which always points radially inward, keeps the object from breaking out of the circular path

Answer 119

- When the waves are perfectly in phase, the displacements always add together and the amplitude of the resultant is equal to the sum of the ampluitudes of the two waves

Answer 120

- Made of atoms with no unpaired electrons and that have no net magnetic fields - Are slightly repelled by a magnet, so can be called weakly antimagnetic - Examples: wood, plastics, water, glass and skin

Answer 121

- Uses high frequency sound waves outside the range of human hearing to compare the relative densities of tissues in the body - Ultrasound machine consists of a transmitter that generates a pressure gradient, which also functions as a receiver that processes the reflected sound - Because the speed of the wave and the travel time is known, the machine can generate a graphical representation of borders and edges within the body, by calculating the transversed distance - Relies of refelction in order to visualize anything, so an interface between two objects is necessary

Answer 122

- THe electric field between the plates of a parallel plate capacitor is a uniform electric field with parallel field vectors - The magnitude can be calculated by: E=V/d V: voltage d: distance - Note: the direction of the electric field at any point between the plates is from the positive plate toward the negative plate

Answer 123

- When light of a sufficiently high frequency (typicallly, blue to ultraviolet light) is incident on a metal in a vacuum, the metal atoms emit electrons - Electronsliberated from the metal by the photoelectric effect will produce a net charge per time (a current) - The higher the intensity of the light beam, the greater the number of photons per unit time that fall on an electrode, the greater numer of electrons per unit time liberated from the metal

Answer 124

- Because the electical potential is inversely prorpotional to the distance from the source charge, a potential difference will exist between two points that are at different distacnes from the source charge (Remember: V=kQ/r) - If V_a and V_b are the electrical potentials at points a and b, respectively, then the potential differnece between them is the Voltage (V_b- V_aor ΔV) ΔV = V_b- V_a= W_ab/q Wab: the work needed to move a test charge, q, through an electic field from point a to point b

Answer 125

- When an object is placed in fluid, it will sink into the fluid only to the point at which the volume of the displaced fluid exerts a force that is equal to the weight of the object F_buoy= ρ_fluid V_{fluid displaced} g = ρ_fluid V_submergedg

Answer 126

The spontaneous dispersal of energy at a specific temperature; how much energy is spread out or how widely spread out energy becomes in a process ΔS= Q_rev/T ΔS: entropy Q_rev: the heat that is gained or lost in a reversible process T: the temperature in kelvin Units: J/mol x K Example: While water and ice at 0C have the same kinetic energy, the energy is dispered over a larger number of microstates in liquid water; therefore water has a higher entropy and by extension, it is indeed less organized than ice

Answer 127

50 - 10^-2 nm

Answer 128

- Quantifies the magnitude of electrostatic force, F_e, between two charges F_e= kq₁q₂/r² k: Coulomb's constant (8.99 x 10⁹N x m²/C²) q1 and q2: magnitudes of the two charges r: is the distance between the two charges

Answer 129

- a dispersive effect within a spherical lens; depending on the thickness and curvature of the lens, there may be signficant splitting of white light, which results in a rainbow halo around images - Corrected for in visual lenses liek eyeglasses and car windows with special coatings that have different dispersive qualities than the lens itself

Answer 130

- All the possible frequencies that a string can support (n=1, n=2, n=3...) with regard to: f=nv/2L

Answer 131

- Concave mirrors are converging mirrors, because they cause parallel incident light rays to converge - Convex mirrors are diverging mirrors, because they cause parallel incident light rays to diverge

Answer 132

- Dielectric material: insulation - When a dielectric material, such as air, glass, plastic, ceramic, or certain metal oxides, is introduced between the plates of the capacitor, it increases the capacitance by a factor called the dielctric constant (κ) C' = κC C': new capacitance C: initial capacitance

Answer 133

- Describes how far a particular point on the wave is from the equilibrium position, expressed as a vector quantity - Maximum displacement is the amplitude Symbol: x

Answer 134

- The particular type of vibration that occurs when an object is hit and thus begins to vibrate - This can be altered by changing some aspect of the object, for example, by putting in more or less water into a wine glass or tightening or loosening a string

Answer 135

- A naturally occurring spontaneous decay of certain nuclei accompanies by the emission of specific particles

Answer 136

3. 00 x 10⁸m/s - While EM waves vary in frequency and wavelength, in a vacuum, all EM waves travel at the speed of light

Answer 137

- Waves in which the direction of particle oscillation is perpendicular tot he propagation of the wave - Example: a wave in the stadium; the people (particles) go up and down, but the wave moves left to right (Image B)

Answer 138

- The energy stored by springs and other elastic systems - Every spring has a a characteristic length at which it is considered relaxed, or in equilibrium. When a spring is stretched from its equilibrium length, the spring has spring potential energy U=1/2 kx² U: potential energy k: spring oconstant (a measure of the stiffness of a spring) x: magnitude of displacement from equilibrium

Answer 139

- When a large nulceus splits into smaller nuclei - Rarely occurs sponteaneously, but through the absorption of a low-energy neutron, fision can be induced in certain nuclei - Because the binding energy per nucleon is greatest for intermediate-sized atoms (intermediate-sized atoms are most stable), when small atoms combine or large atoms split, a great amount of energy is released

Answer 140

1mm - 700nm

Answer 141

_Focal length (f)_: the distance between the focal point and the mirror *Note: f = r/2* _Center of Curvature (C)_: a point on the optical ais located at a distance equal to the radius of curvature from the vertex of the mirror **1/f = 1/o +1/i = 2/r** o: the distance between the object and the mirror i: the distance between the image and the mirror

Answer 142

- The frequency that is often used in consideration of simple harmonicmotion in springs and pendula ω= 2π/T=2πf T: period f: frequency (Remember: T=1/f)

Answer 143

- Takes into account the pathway traveled (which displacement does not) - Scalar quantity

Answer 144

A form of potential energy that is dependent on the relative position of one charge with respect to another charge or collection of charges U = kQq/r - If charges are unlike (one positive and one negative) that potential energy will be negative - If the charges are alike (both positive or both negative), then the potential energy will be positive

Answer 145

β_f = β_i +10log(I_f/I_i) I_f/I_i: the ratio of the final intensity to the initial intensity

Answer 146

F= 9/5C +32 K= C+ 273

Answer 147

- Because displacement is pathway independent, the actual distance traveled from the initial to final position does not matter, assuming all forces are conservative - Therefore, aaplying a lesser force over a greater distance to achieve the same change in position (displacement) accomplishes the same amount of work

Answer 148

400 - 50nm

Answer 149

- Viscosity: the resistance of a fluid to flow - Increased viscosity of a fluid increases its viscous drag, a non-conservative force that is analogous to air resistance

Answer 150

- When a first object is thermal equilibrium with a second object and the second object is in equilibrium with the third, the first is also in equilibrium the the third and there will be no heat flowing between the objects

Answer 151

The change in the total internal energy of a system is equal to the amount of energy transferred in the form of heat to the system, minus the amount of energy transferred from the system in the form of work - A statement of the conservation of energy: the total energy in the unveise can never decrease or increase

Answer 152

- Consist of multiple slits arranged in patterns - Can create color patterns similar to a prism as the different wavelengths interfere in characteristic patterns _Examples_ - CD or DVD; these act like diffraction grating - thin films may also cause interference patterns, because light waves reflecting off the external surface of the film interfere with light waves reflecting off the internal surface of the film (thin films are things like bubbles or oil puddles in puddles of water)

Answer 153

20Hz to 20,000Hz

Answer 154

The voltage drop between any two points in a circuit, given that electrical resistance results in an energy loss, which reflects a drop in electrical potential V= IR V: voltage drop I: the current R: the magnitude of resistance

Answer 155

- The minimum frequency of light that causes ejection of electrons - Symbol: f_T - Depends on the type of metal being exposed to radiation - If the frequency of the incident photon is less than the threshold frequency, then no electron is emitted - If the frequency of the incident photon is more than the threshold frequency, then an electron will be ejected, and the maximum kinetic energy of the ejected electron will be equal to the difference between hf and hf_T Remember: E=hf E: energy of the photon of light h: Planck's constant, 6.626 x 10^-34 J s

Answer 156

- The total pressure that is exerted on an object that is submerged in fluid (remember: fluids are both liquids and gases) **P= P_o + ρgz** P= absolute pressure P_o= ambient pressure (pressure at the surface) ρ = density of the fluid g = acceleration due to gravity z= depth of the object

Answer 157

Density: the ratio of mass to volume ρ= m/V Density of water: 1 g/ cm³

Answer 158

Measure of force N = kg⋅m/s²

Answer 159

- An object that is producing sound while traveling at or above the speed of sound allows wave fronts to build upon one another at the front of the object - This creates a much larger amplitude at that point - This highly condensed wave front is the shock wave - Can cause physical disturbances as it passes through objects

Answer 160

- Light waves that are refelcted are not absorbed into the second medium; rather they bound off of the boundary and travel back throguh the first medium - Law of reflection: θ₁ = θ₂ θ₁: incident angle, measured from the normal θ₂: reflected angle, measured from the normal normal: line perpendicular to the surface

Answer 161

- When a species absorbs a high-frequency light and then returns to its grounds state in multiple steps - Each step has less energy than the absorbed light and is within the visible range of electromagnetic spectrum

Answer 162

A longitudinal wave transmitted by the oscillation of particles in a deformable medium; sound can travel through solids, liquids, and gases but cannot travel through a vacuum

Answer 163

700nm to 400nm

Answer 164

- Used to measure a voltage drop across two points in a circuit (wired in parallel to these two points) - Voltmeters use magnetic properties of a current-carrying wire; require a circut to be active - Ideally; has infinite resitance

Answer 165

When the electric fields of all the waves are oriented int he same diection (their electric field vectors are all parallel)

Answer 166

Increasing ΔSuniverse = ΔS_system+ ΔS_surrounds \> 0

Answer 167

- When the frequency of periodic force is equal to a natural (resonant) frequency of the system - Example: shattering of a wine glass by loudly singing the natural frequency of the class; the glass will resonate (oscillate with maximum amplitude) and eventually shatter

Answer 168

For resistors in series, the current has no choice but to go through every resistor **Rs = R₁+R₂+R₃+R₄...** For resistors in parallel, we allow for more pathways for current to take **1/R_p= 1/R₁ + 1/R₂ +1/R₃+ 1/R₄**

Answer 169

a_avg= Δv/Δt

Answer 170

c= fλ c: speed of light f: frequency λ: wavelength

Answer 171

- Subtracting one vector from another can be accomplished by adding a vector with equal magnitude - but opposite direction - to the first vector A - B = A + (-B)

Answer 172

**a sinθ = nλ** a: width of the slit θ: the angle between the line drawn from the center of the lens to the dark fringe and the axis of the lens n: an integer indicating the number of the fringe: λ: wavelength of the incident light

Answer 173

- When certain unstable radionuclides capture an inner electron that combines with a proton to form a neutron (while releasing a neutrino) - The atomic number is one les than the original, but the mass number is the same - Kind of like a reverse β-decay

Answer 174

A line on which the potential at every point is the same; the potential difference between any two points on an equipotential line is zero

Answer 175

- Isothermal (ΔU= 0) so first law reduces to Q=W - Adiabatic (Q=0) so first law reduces to ΔU=-W - Isobaric (constant pressure); no special form Isovolumetric (W=0) so first law reduces to ΔU=Q Remember, first law of thermodynamics is ΔU= Q - W

Answer 176

x= m₁x₁ +m₂x₂+m₃x₃.../ m₁+m₂+m3... y= m₁y₁ +m₂y₂+m₃y₃.../ m₁+m₂+m3... z= m₁z₁ +m₂z₂+m₃z₃.../ m₁+m₂+m3...

Answer 177

1.013 x 10⁵ Pa= 760 mmHg= 760 torr= 1 atm

Answer 178

- At any point or junction into a circuit, the sum of currents directed into that point equals the sum of currents directed away from that point I _{into junction}= I_{out of junction}

Answer 179

Conservative forces: gravity and electrostatic forces Non-conservative: frction and air resistance

Answer 180

**Real image**: an image is said to be real if the light actually converges at the point of the image - Distinguishing feature: real images can be projected onto a screen **Virtual image**: an image is said to be virtual if the light only appears to be coming fromt eh position of the image but does not actually converge there

Answer 181

- Two waves that have the same frequency, same wavelength, and amplitude and that pass throught he same space at the same time, whose crests and troughs line up.

Answer 182

Kinetic energy: the energy of motion; objects that have a mass and that are moving with some speed will have an associated amount of kinetic energy K=1/2mv² K: kinetic energy m: mass in kilograms v: speed in meters/second SI Unit: Joule (kg⋅m²)/s²

Answer 183

When no cahrge is moving between the two terminals of a cell that are at different potential values - A potential difference (voltage)

Answer 184

- The amount that a conductive material, such as copper wires, act as weak resistors themselves, offers some magnitude of resistance to current and causing a drop in electrical potential (voltage) V: E_cell - ir_int V: voltage provided by the cell E cell: emf of the cell i: the current through the cell r_int: the internal resitance of the cell

Answer 185

Characterized by their ability to hold charge ast a particular voltage - Example: defibrillators; they charge, the charge can be released in one surge of power

Answer 186

- The difference between the mass of unbound nucleons (protons and neutrons) and the mass of boudn nucleons within the nucleus - The unbound constituents have more energy and, therefore, mroe mass thant he boudn constituents - The mass defect is the amoung of mass converted to energy during nuclear fusion (E=mc²)

Answer 187

- Have unpaired electrons and permanent atomic magnetic dipoles that are normally oriented randomly, so the material has no net magnetic dipole (like paramagnetic materials) - Will become strongly magnetized when exposed to magnetic field or under certain temperatures (unlike paramagnetic materials) - Examples: iron, nickle and cobalt

Answer 188

- Intensity is proportional to the square of the amplitude - Thus, a doubling of the amplitude produces a sound wave that has four times the intensity

Answer 189

- Describes the difference between the actual frequency of a sound and its perceived frequency, when the source of the sound and the sound’s detector are moving relative to one another * f_o: perceived frequency * f_s: emitted frequency

Answer 190

ρ_object / ρ_fluid = V_disp/V

Math/Physics Flashcards

(229 cards)