Energy

Question 1

What are the 8 stores of energy?

Answer 1

• Gravitational potential energy store
• Chemical energy store
• Kinetic energy store
• Elastic potential energy store
• Magnetic energy store
• Electrostatic energy store
• Thermal energy store
• Nuclear energy store

Question 2

What store of energy is found in food, batteries and fuels?

Answer 2

Chemical energy store

Question 3

An ambulance is travelling at 70kph to reach an emergency. It has energy in it’s __________ energy store.

Answer 3

Kinetic

Question 4

A stretched elastic band has energy in it’s _________ energy store

Answer 4

Elastic

Question 5

Two magnets that attract or repel each other have energy in their _________ energy stores.

Answer 5

Magnetic

Question 6

Everything has some energy in its _________ energy store.

Answer 6

Thermal

Question 7

A ball at the top of a hill has energy in its ____________ energy store.

Answer 7

Gravitational potential

Question 8

Energy can be transferred between energy stores. What are the 4 pathways through which energy can be transferred?

Answer 8

• Mechanical pathway
• By heating
• Electrically
• By radiation

Question 9

When is energy transferred mechanically?

Answer 9

When a force makes something move. E.g. if an object is pushed, pulled, stretched or squashed.

Question 10

What is energy transferred by heating?

Answer 10

When energy is transferred from a hotter object to a colder object.

Question 11

When is energy transferred electrically?

Answer 11

When electrical charges move around an electric circuit due to a potential difference.

Question 12

When is energy transferred by radiation?

Answer 12

When light or sound waves carry energy from one place to another.

Question 13

Explain why an ice-pop melts if left on a kitchen table?

Answer 13

When there is a temperature difference between two objects energy will be transferred from the thermal store of the hotter object to the thermal store of the colder object.

This continues until both object reach the same temperature.

Question 14

Describe how energy is transferred by conduction.

Answer 14

When an object is heated its particles gain energy in their kinetic stores. They start to vibrate more and bump into neighbouring particles. In this way the energy is transferred.

Question 15

Define radiation in terms of energy transfer.

Answer 15

Radiation is the transfer of energy by waves (not particles). The energy from the sun reaches the earth by radiation.

Question 16

What type of object emit or absorb radiation?

Answer 16

All objects emit (give out) radiation and object absorb radiation too.

Some objects are better or worse at emitting or absorbing radiation.

Question 17

How is radiation different to conduction and convection?

Answer 17

It transfers energy by waves, NOT particles.

Question 18

What type of surfaces are better absorbers and emitters of infrared radiation?

Answer 18

Matt dark surfaces are better absorbers and emitters of infrared radiation than shiny light surfaces.

Question 19

Which words would fit best for the blanks below:

White (or silver) and shiny surfaces do not _________radiation well and _________ radiation instead of absorbing it.

Answer 19

White (or silver) and shiny surfaces do not emit radiation well and reflect radiation instead of absorbing it.

Question 20

State the principle of conservation of energy.

Answer 20

Energy can not be created nor destroyed, it can only be transferred from one energy store to another.

Question 21

Right now we generate most of our electricity by burning _______ _________.

Answer 21

Fossil fuels

Question 22

What are renewable energy resources?

Answer 22

Renewable energy resources are resources that are being used up at the same rate as they can be replaced.

Question 23

Give some examples of renewable energy resources.

Answer 23

• Sun (solar energy)
• Water (tidal energy)
• Wind
• Biomass
• Hydroelectric
• Geothermal

Question 24

What is meant by a ‘non renewable’ energy resource?

Answer 24

Non-renewableenergy resources cannot be replaced once they are all used up.

Question 25

What are the 4 forms of non-renewable energy resources.

Answer 25

• Coal
• Oil
• Gas
• Nuclear

Question 26

Name the 3 fossil fuels that are non-renewable energy resources.

Answer 26

Coal, Oil, Gas are all fossil fuels.

Question 27

Which word means ‘there is a limited amount’ in terms of energy resources.

Answer 27

Finite

Question 28

Give 2 examples of non-renewable nuclear fuels.

Answer 28

• Uranium

- Plutonium

Question 29

Which energy store is in fossil fuels?

Answer 29

Chemical energy store

Question 30

Name 2 ways we could reduce the amount of fossil fuels we use.

Answer 30

• Save energy (turn off lights, drive electric cars etc).
• Recycle
• Use more renewable energy

Question 31

What is an ‘electrical appliance’?

Answer 31

Anything that required electricity to work. E.g. a television.

Question 32

What does ‘power’ tell us?

Answer 32

How fast an appliance transfers energy.

Question 33

What are the units of power?

Answer 33

Watts (W) or kilowatts (kW).

Question 34

1kW = ? W

Answer 34

1kW = 1000 W

Question 35

What does the total amount of energy transferred by an appliance depend on?

Answer 35

The total amount of energy transferred by an appliance depends on how long it is running for (time) and it’s power.

Question 36

What is the formula to calculate energy transferred by an electrical appliance?

Answer 36

Energy transferred (J) = Power (W) x time (s)

Question 37

A 2000W kettle boils in 150 seconds. Use the formula to calculate the energy transferred.

Answer 37

Energy transferred (J) = Power (W) x time (s)

                                =  2000W   x   150 s
                                = 300,000 J