Topic 5 Energy

Question 1

What unit is energy measured in.

Answer 1

Joules (J)

Question 2

What is the definition of energy

Answer 2

Energy cannot be created or destroyed. It can only be transferred from one type to another

Question 3

Which energy raises the temperature of an object

Answer 3

Thermal or heat

Question 4

Which energy does an object have when it is moving

Answer 4

Kinetic

Question 5

Which energy is produced by vibrations

Answer 5

Sound

Question 6

Which energy allows us to see things

Answer 6

Light

Question 7

Which energy is found in batteries, fuel or food

Answer 7

Chemical

Question 8

Which energy is carried in an electrical circuit

Answer 8

Electrical

Question 9

Which energy is in an object that is high up and about to fall?

Answer 9

Gravitational potential

Question 10

Which energy is in a stretched elastic band

Answer 10

Elastic potential

Question 11

In an energy transfer diagram you have to state what the input energy is and the output energy is.
For a TV state the input and output energy that you would include in an energy transfer diagram

Answer 11

Input is ELECTRICAL ————> Output energy is LIGHT AND SOUND ENERGY

Question 12

What is the energy transfer diagram for a stretched elastic band that is then released

Answer 12

ELASTIC POTENTIAL ——-> KINETIC ENERGY

Question 13

How many Joules are there in a kilojoule

Answer 13

1000J

Question 14

What is the energy transfer in a person eating a plate of pasta

Answer 14

CHEMICAL ENERGY ———->HEAT ENERGY + KINETIC ENERGY

Question 15

Not all energy is useful when used and some is wasted. In a TV can you name a waste form of energy that would be produced

Answer 15

heat energy

Question 16

Efficiency measures how much of the energy that is input into an object is used usefully in the output energy.
If an object has an input energy of 100 J and only 40J is used usefully, how much waste energy is produced

Answer 16

100 J input - 40J useful = 60J waste energy

Question 17

In a machine if 50J is input energy and 25J is useful. What is the % efficiency?

Answer 17

%efficiency = useful energy/ input energy x 100

25J useful/ 50 J input = 0.5
0.5 x100% = 50%

Question 18

What is meant by non renewable energy

Answer 18

Energy that will eventually run out and cannot be replaced

Question 19

Give 3 examples of non renewable energy sources

Answer 19

Coal
Oil
Gas
Nuclear

Question 20

What is meant by renewable energy

Answer 20

Energy that can be replaced and will not run out

Question 21

Give 4 examples of renewable energy

Answer 21

Solar
Wind
Hydroelectric
Tidal
Biomass

Question 22

What is a problem with renewable energy resources

Answer 22

It is not always windy (for windmills)
It is not always light (for solar)
Some people think it is unsightly eg wind farms
Takes up habitat spaces eg hydroelectric dams

Question 23

What is a problem with non renewable resources

Answer 23

Cause pollution of air
Will eventually run out

Question 24

How is coal formed

Answer 24

Dead plants and animals that died millions of years ago
Did not decay but got buried under mud and earth
Pressure and heat over time changed them to coal

Question 25

How is oil formed

Answer 25

Dead animals in sea millions of years ago
Sink to bottom of sea
Buried under sand
Pressure converted over time to oil