Physics Complete

Question 1

What are the 8 types of energy stores?

Answer 1

Kinetic, Thermal (internal), Chemical, Gravitational potential, Elastic potential, Magnetic, Electrostatic, Nuclear.

Question 2

What is an energy store?

Answer 2

A way that energy is held by an object or system, such as kinetic, thermal, or chemical.

Question 3

List the 4 main ways energy can be transferred.

Answer 3

Mechanical (force), Electrical (current), Heating (thermal), Radiation (light/sound).

Question 4

What is the principle of conservation of energy?

Answer 4

Energy cannot be created or destroyed, only transferred, stored, or dissipated.

Question 5

What does a rollercoaster energy diagram show?

Answer 5

It shows how energy changes between gravitational potential, kinetic, and thermal as the car moves along the track.

Question 6

What is a closed system?

Answer 6

A system where no energy enters or leaves; the total energy remains the same.

Question 7

What does ‘dissipated’ mean in energy transfer?

Answer 7

Energy is spread out and lost to the surroundings, usually as heat, so it is less useful.

Question 8

What does ‘degraded’ energy mean?

Answer 8

Energy that has become less useful after being transferred, often as wasted thermal energy.

Question 9

Describe energy transfer in a swinging pendulum.

Answer 9

Energy changes from gravitational potential at the top, to kinetic as it swings down, and to thermal as friction acts.

Question 10

Describe the Sankey diagram for an incandescent light bulb.

Answer 10

Shows electrical energy input, with a large arrow for wasted heat energy and a smaller arrow for useful light energy output.

Question 11

What is specific heat capacity?

Answer 11

The amount of energy required to raise the temperature of 1 kg of a substance by 1°C.

Question 12

What is the formula for specific heat capacity?

Answer 12

Q = mcΔT ; Q = energy (J), m = mass (kg), c = specific heat capacity (J/kg°C), ΔT = temperature change (°C).

Question 13

Describe the practical to measure specific heat capacity.

Answer 13

Heat a known mass with an immersion heater, measure temperature rise, calculate using Q = mcΔT.

Question 14

What equipment is used in the specific heat capacity practical?

Answer 14

A block of material with holes for a heater and thermometer, insulation, a power supply, and timer.

Question 15

How do you improve accuracy in the specific heat capacity experiment?

Answer 15

Use insulation, stir the material, start readings at the same time, and repeat for reliability.

Question 16

Give a worked example for specific heat capacity.

Answer 16

If 2100J heats 100g of water by 5°C, c = 2100 / (0.1 x 5) = 4200 J/kg°C.

Question 17

What is internal energy?

Answer 17

The total kinetic and potential energy of all the particles in a system.

Question 18

What happens to internal energy when you heat a system?

Answer 18

It increases, either raising the temperature or changing the state.

Question 19

What is the formula for kinetic energy?

Answer 19

E_k = 1/2 mv^2 ; E_k = kinetic energy (J), m = mass (kg), v = speed (m/s).

Question 20

What is the formula for gravitational potential energy (GPE)?

Answer 20

E_p = mgh ; E_p = GPE (J), m = mass (kg), g = 9.8 N/kg, h = height (m).

Question 21

What is the formula for elastic potential energy?

Answer 21

E_e = 1/2 ke^2 ; E_e = elastic potential energy (J), k = spring constant (N/m), e = extension (m).

Question 22

What are the units for energy?

Answer 22

Joules (J).

Question 23

What is the unit for mass?

Answer 23

Kilograms (kg).

Question 24

What is the unit for speed?

Answer 24

Meters per second (m/s).

Question 25

What is the unit for height?

Answer 25

Meters (m).

Question 26

What is the unit for spring constant?

Answer 26

Newtons per meter (N/m).

Question 27

How does lubrication reduce unwanted energy transfer?

Answer 27

It reduces friction between moving parts, so less energy is wasted as heat.

Question 28

How does insulation reduce unwanted energy transfer?

Answer 28

Insulation reduces the rate of heat loss by trapping air or reducing heat conduction.

Question 29

What is thermal conductivity?

Answer 29

A measure of how easily heat passes through a material.

Question 30

How does building design reduce energy loss?

Answer 30

Using thick walls, insulating materials, and double glazing reduces heat loss.

Question 31

Describe energy transfer in a car engine.

Answer 31

Chemical energy in fuel → kinetic energy (movement), sound energy, and heat energy (wasted).

Question 32

Describe energy transfer in a boiling kettle.

Answer 32

Electrical energy → thermal energy of water.

Question 33

What is the formula for power using energy?

Answer 33

P = E / t ; P = power (W), E = energy (J), t = time (s).

Question 34

What is the formula for power using work?

Answer 34

P = W / t ; W = work done (J).

Question 35

What is the formula for efficiency (energy version)?

Answer 35

Efficiency = (useful energy output / total energy input) × 100.

Question 36

What is the formula for efficiency (power version)?

Answer 36

Efficiency = (useful power output / total power input) × 100.

Question 37

What is the definition of power?

Answer 37

The rate at which energy is transferred or work is done.

Question 38

How can you reduce wasted energy?

Answer 38

By using more efficient devices, insulation, and lubrication.

Question 39

What are renewable energy resources?

Answer 39

Resources that can be replenished and won't run out, e.g. solar, wind, hydroelectric, geothermal, tidal, biofuel, water waves.

Question 40

What are non-renewable energy resources?

Answer 40

Resources that will eventually run out, e.g. coal, oil, gas, nuclear.

Question 41

Name a pro of renewable energy resources.

Answer 41

Low environmental impact, won’t run out, less greenhouse gas.

Question 42

Name a con of renewable energy resources.

Answer 42

Often less reliable, can require large areas, depends on weather.

Question 43

Name a pro of non-renewable energy resources.

Answer 43

Reliable output, high energy density, can produce lots of electricity on demand.

Question 44

Name a con of non-renewable energy resources.

Answer 44

Releases greenhouse gases, causes pollution, will run out.

Question 45

Give an example of an energy resource and its use.

Answer 45

Coal: used for electricity generation and heating.

Question 46

Give one ethical issue related to hydroelectric power.

Answer 46

Flooding land displaces people and wildlife.

Question 47

What are the three types of nuclear radiation?

Answer 47

Alpha (α), Beta (β), Gamma (γ).

Question 48

What are the properties of alpha radiation?

Answer 48

Strongly ionising, weakly penetrating (stopped by paper).

Question 49

What are the properties of beta radiation?

Answer 49

Moderately ionising and penetrating (stopped by aluminium).

Question 50

What are the properties of gamma radiation?

Answer 50

Weakly ionising, highly penetrating (stopped by thick lead/concrete).

Question 51

What is the nuclear equation for alpha decay?

Answer 51

The atom loses 4 from its mass number and 2 from its atomic number. E.g. 238/92U → 234/90Th + α.

Question 52

What is the nuclear equation for beta decay?

Answer 52

The mass number stays the same, atomic number increases by 1.

Question 53

What is half-life?

Answer 53

The time taken for half of the radioactive nuclei in a sample to decay.

Question 54

How do you calculate remaining activity after n half-lives?

Answer 54

Remaining activity = Initial activity × (1/2)^n.

Question 55

What is background radiation?

Answer 55

Radiation that is always present from natural and artificial sources.

Question 56

Name some sources of background radiation.

Answer 56

Cosmic rays, radon gas, rocks, medical uses, food.

Question 57

Give one use of alpha radiation.

Answer 57

Smoke alarms.

Question 58

Give one use of beta radiation.

Answer 58

Measuring thickness of materials in industry.

Question 59

Give one use of gamma radiation.

Answer 59

Medical tracers and sterilising equipment.

Question 60

Write the formula for kinetic energy.

Answer 60

E_k = 1/2 mv^2

Question 61

Write the formula for gravitational potential energy.

Answer 61

E_p = mgh

Question 62

Write the formula for elastic potential energy.

Answer 62

E_e = 1/2 ke^2

Question 63

Write the formula for specific heat capacity.

Answer 63

Q = mcΔT

Question 64

Write both formulas for power.

Answer 64

P = E/t ; P = W/t

Question 65

Write the formula for efficiency (energy).

Answer 65

Efficiency = (useful output / total input) × 100

Question 66

Write the formula for remaining activity after n half-lives.

Answer 66

Remaining Activity = Initial × (1/2)^n

Question 67

Define 'system' (physics)

Answer 67

An object or group of objects.

Question 68

What does 'energy dissipated' mean?

Answer 68

Energy transferred to the surroundings and spread out as less useful energy.

Question 69

What does 'work done' mean in physics?

Answer 69

The amount of energy transferred by a force acting over a distance.

Question 70

What does 'thermal energy' mean?

Answer 70

Energy stored in the movement of particles in a substance (internal energy).

Question 71

Explain the term 'reproducible' in experiments.

Answer 71

If an experiment is reproducible, repeating it gives the same result.

Question 72

What is meant by 'anomalous result'?

Answer 72

A result that does not fit the pattern and should be investigated.

Question 73

What is a 'half-life' in radioactivity?

Answer 73

The time it takes for the activity (or number of nuclei) to fall to half its original value.

Question 74

Describe a Sankey diagram for a light bulb.

Answer 74

Shows total input energy as a thick arrow, split into a thin arrow for useful output (light) and a thicker arrow for wasted output (heat).

Question 75

Describe the setup for a specific heat capacity experiment.

Answer 75

A metal block with holes for a heater and thermometer, wrapped in insulation, connected to a power supply.

Question 76

Describe the energy transfers in a rollercoaster.

Answer 76

At the top: mostly gravitational potential energy. As it descends: converted to kinetic energy. At the bottom: some kinetic, some lost as heat and sound.

Question 77

A 20W light bulb transfers 15W usefully as light. What happens to the rest?

Answer 77

It is dissipated as heat energy to the surroundings.

Question 78

Calculate the energy needed to heat 1.5kg of water from 20°C to 100°C. (c = 4200J/kg°C)

Answer 78

Q = mcΔT = 1.5 × 4200 × 80 = 504,000J.

Question 79

Explain what is meant by 'reproducible' and why it is important.

Answer 79

It means the experiment can be repeated with the same result by others. Important for reliability.