Topic 1-Energy

Question 1

What is specific heat capacity?

Answer 1

Amount of energy needed to raise the temp of 1kg of a substance by 1 degree Celsius

Question 2

What is power?

Answer 2

The rate at which work is done/ energy is transferred

Question 3

Describe the energy changes when ball is thrown upwards?

Answer 3

Kinetic energy is converted to GPE
When at peak, its maximum GPE
GPE is converted back to kinetic energy

Question 4

State 4 different energy stores

Answer 4

Chemical store
Kinetic store
GPE store
EPE store

Question 5

State the law of energy conservation

Answer 5

Energy cannot be created or destroyed , only transferred to different forms

Question 6

What is waste energy?

Answer 6

Energy not used by device for desired purpose

Question 7

How can the efficiency of a system be increased

Answer 7

Reducing waste output (lubrication/ thermal insulation)

Question 8

State 3 methods of reducing heat loss in a building

Answer 8

1. Double glazing
2. Loft and wall insulation
3. Thicker walls

Question 9

How can lubricating reduce energy transfer?

Answer 9

Reduces friction and therefore energy loss due to heating

Question 10

What is a renewable energy source?

Answer 10

An energy source which can be replenished as it is being used up

Question 11

Give 4 examples of renewable energy sources

Answer 11

Wind
Solar
Tidal
Geothermal

Question 12

Give and example of a non renewable energy resource

Answer 12

Fossil fuels (coal, oil, gas)

Question 13

State 2 disadvantages of using renewable energy resources

Answer 13

Output determined by external factors (wind) so unreliable

Very costly

Question 14

What are the environmental impacts of burning fossil fuel?

Answer 14

CO2 contributes to greenhouse effect and therefore global warming

Question 15

State 3 advantages of fossil fuel as a resource

Answer 15

Reliable- can generate power any time
Can produce large amounts of energy
Cost effective

Question 16

What are 3 advantages of nuclear power?

Answer 16

Large amounts of energy for small amount of fuel
Doesn’t release greenhouse gases and contribute to climate change
Cost efficient

Question 17

What are 2 disadvantages of nuclear power?

Answer 17

Nuclear waste is harmful to humans
Risk of nuclear accidents
Non renewable

Question 18

How does hydroelectric power produce energy?

Answer 18

Rainwater collects behind dam
water is released and turns turbine
Turbine turns generator and produces electricity

Question 19

Describe energy transfers for a bungee jumper

Answer 19

Falling- GPE converted to KE
Cord tightens- KE converted and stores as EPE
Lowest point- initial GPE equals EPE stored in cord

Question 20

Why does a bungee jumper slow down when the cord begins to stretch?

Answer 20

KE decreases as it is converted to EPE

Since KE is proportional to velocity, when KE decreases, so does velocity

Question 21

Give examples of chemical energy stores

Answer 21

1. Food
2. Fuel
3. Batteries

Question 22

Describe energy changes that occur in a filament lamp

Answer 22

Electrical energy transferred to light and heat energy

Light- useful, heat- waste

Question 23

What can be said about the energy transfer of a material with high thermal conductivity?

Answer 23

Rate of energy transfer through material is higher for a material with higher thermal conductivity

Question 24

Do double glazed windows have a higher or lower thermal conductivity than single-glazed windows?

Answer 24

Lower- meaning less energy transfers through them

Question 25

What 2 factors affect the rate of cooling of a building?

Answer 25

1. Thickness of the walls | 2. Thermal conductivity of the walls

Question 26

How can the efficiency of a mechanical machine with moving parts be improved?

Answer 26

Lubrication of moving parts- reduce friction and therefore energy loss due to heating

Question 27

How can efficiency of radiator be improved?

Answer 27

Install metal foil sheets behind radiator- reflect heat back into room rather than it being absorbed into walls

Question 28

What are the advantages of generating power using gas rather than coal?

Answer 28

1. Gas power stations have short start up times | 2. Lower emissions of CO2

Question 29

What are 2 disadvantages of using biofuels?

Answer 29

1. In order to grow biofuels you need to destroy land | 2. When plants are burned they release CO2

Question 30

What are the advantages of tidal energy sources?

Answer 30

1. Dont produce greenhouse gases | 2. Reliable, as tides happen twice a day

Question 31

What are disadvantages of hydroelectric power?

Answer 31

1. Dam may cause flooding | 2. Can cost a lot to install required infrastructure

Question 32

What are the advantages of solar panels?

Answer 32

1. Don’t cause environmental harm | 2. Can be used in remote areas

Question 33

Give examples of social factors which may act as deterrents for some energy production

Answer 33

1. Visual pollution | 2. Sound pollution