Physics

Question 1

What is density?

Answer 1

Density is a measure of how compact the particles are in a substance it considers the mass given in a given volume

Question 2

What is the most dense state of matter?

Answer 2

Solid

Question 3

What is the least dense state of matter?

Answer 3

Gas

Question 4

What is the calculation for density?

Answer 4

Mass/volume=density

Question 5

What is density measured in?

Answer 5

Kg/m3

Question 6

What is internal energy?

Answer 6

Internal energy is the energy stored inside a system by the particals (atoms and molecules) that make up a system.

Question 7

What is the calculation for internal energy?

Answer 7

Kinetic +potentual=internal energy

Question 8

What is latent heat?

Answer 8

Latent heat is the energy needed for a substance to change state without a temperature change.

Question 9

Latent heat of vapporation

Answer 9

When a liquid turns into a gas without changing temperature.

Question 10

Latent heat of fusion

Answer 10

When a solid changes to a liquid without changing temperature.

Question 11

The specific latent heat of a substance

Answer 11

The amount of energy required to change the state of one kg of the substance with no change in temperature.

Question 12

The calculation for change in thermal energy

Answer 12

Change in thermal energy=mass x specific heat capacity x temp change

Question 13

The calculation for energy transfured

Answer 13

Energy transfused = current x voltage x time

Question 14

Calculation for change in thermal energy?

Answer 14

Change in thermal energy= mass x specific heat capacity x temp change.

Question 15

What is the calculation of pressure?

Answer 15

Pressure = force / area

Question 16

What is pressure measured in?

Answer 16

N/m2 or pa (pascals)

Question 17

Arrangement of the 3 states of matter?

Answer 17

Gas: spread out ,almost no force or attraction ,large distance between particals
Liquid: particals are in contact ,weaker forces of attraction
Solid: particals held together in rows

Question 18

Movement of the different states of matter?

Answer 18

Gas: particals move randomly
Liquid: particals move randomly
Solid: particals vibrate

Question 19

What are the properties of the three state of matters?

Answer 19

Gas: low density ,no fixed volume or shape ,can be compressed ,spread out
Liquid: usually lower density than solids fixed volume ,shape not fixed
Solid: high density ,fixed volume ,fixed shape

Question 20

What is the definition of energy?

Answer 20

The strength and vitality required for sustained physical or mental activity

Question 21

How do you convert j into kj?

Answer 21

Divide by 1000

Question 22

What are the 3 units of energy?

Answer 22

Joules ,kWh ,calorie

Question 23

What does kilo in Greek mean?

Answer 23

It means thousand

Question 24

What is an open system?

Answer 24

When energy and matter can freely move in and out of a system

Question 25

What is a closed system?

Answer 25

When only energy can be exchanged in and out of a system

Question 26

What is an isolated system?

Answer 26

When neither energy or matter can exchange in and out of a system

Question 27

What is dissipated energy?

Answer 27

When the the energy be created is unnecessary/wasted

Question 28

What is pendulum?

Answer 28

Mass of something attached to so thing that moves

Question 29

What is the calculation of efficiency?

Answer 29

Efficiency= useful output energy j / total input energy

Question 30

What is the calculation for power?

Answer 30

Power= energy / time

Question 31

What is the calculation for energy?

Answer 31

Energy = power x time

Question 32

What is the calculation for gravitational potential energy?

Answer 32

Gp= mass x gravitational field strength x height

Question 33

What are the 8 different energy stores?

Answer 33

Magnetic Gravitational potential Electrostatic Chemical Nuclear Thermal Elastic potential Kinetic

Question 34

What is the calculation for kinetic energy?

Answer 34

Ke= 0.5 x mass x velocity squared Ek=1/2xmv2

Question 35

What is the calculation of elastic potential energy?

Answer 35

Ep=0.5 x spring constant x extension Ee=1/2 ke2 (Objects that can be pressed ,compressed or twisted and return to its original shape are considered to be elastic)

Question 36

Define and calculate power?

Answer 36

Power(p)= change in energy (e) + time interval (t) P=e/t Power is either the rate at which energy is transferred to an object or work done by an object per unit time interval

Question 37

What are power and energy measured in?

Answer 37

Power is measured in watts (w) Energy is measured in joules (j) P= e/t = w/t (E is energy ,t is time and w is work done)

Question 38

What is a conductor?

Answer 38

Material which allows high rate of energy transfer

Question 39

What does dissipate mean?

Answer 39

Energy being realised

Question 40

What is tidal power?

Answer 40

Power of currents/waves to turn turbines to create electricity

Question 41

What is hydroelectric power?

Answer 41

It creates energy by holding a large amount of water at a height to create gravitational potential energy then let it go turning that gp energy into kinetic ,the flowing water is turned into a turbine to generate power Pros-renewable energy source Cons-wires in the sea ,kills marine life ,stops the natural flow of water

Question 42

What are biofuels and how are they made?

Answer 42

Biofuels are made from living organisms that take a short period of time to form. Biofuels include: Methan gas from manure ,sewage or decaying rubbish Waste veg oil Biofuels are renewable due to there short period of time to form They are carbon neutral-take in co2

Question 43

How are fossil fuels made?

Answer 43

Animal remains where chemically altered and slowly changed into crude oil (High pressure + being trapped = chemically altered animal remains)

Question 44

How is coal made?

Answer 44

Coal is made from trees. When trees fall down they get buried in mud and rocks burying it deeper meaning it gets hotter and higher pressure which turn the trees into coal Coal is mostly made of carbon

Question 45

Factors of fossil fuels?

Answer 45

They are non renewable Have a high yield per bar Formed from organisms Contain carbon and hydrogen

Question 46

Factors of nuclear?

Answer 46

Transfer nuclear potential energy to thermal energy Non renewable Extremely high yielding bar per kg (10000 times an average fossil fuel) Don’t realise co2 Require technical expertise to be used safely Mainly used for electric