7I - Energy and food

Question 1

From where do our bodies get the energy they need?

Answer 1

From the chemical energy stored in food.

Question 2

What is the unit for measuring energy?

Answer 2

Joule (J)

Question 3

Why do we use kilojoules (kJ) instead of joules to measure the amount of energy in food?

Answer 3

There is a lot of energy stored in food.

Question 4

how many joules in 1 kilojoule?

Answer 4

1000 J

Question 5

What 5 things can transfer energy?

Answer 5

• Heat
• Light
• Sound
• Electricity
• Forces

Question 6

How is the energy stored in food, fuels and batteries called?

Answer 6

Chemical energy

Question 7

How is the energy stored in moving objects called?

Answer 7

Kinetic energy

Question 8

How is te enrgy stored in hot objects called?

Answer 8

Thermal energy

Question 9

How is the energy stored in objects that are stretched, squashed or twisted called?

Answer 9

elastic potential energy

(sometimes called strain energy)

Question 10

How is the energy stored in objects that are moved to high places called?

Answer 10

Gravitational potential energy

Question 11

How is the energy stored inside the particles that everything is made from called?

Answer 11

Nuclear energy

(sometimes called atomic energy)

Question 12

What does the law of conservation of energy state?

Answer 12

Energy is not used up. It can be transferred or stored in different ways, but it cannot be created or destroyed.

Question 13

What is a fuel?

Answer 13

A substance that stores energy and releases this energy when it burns.

(i.e. coal, wood, oil)

Question 14

What are fossil fuels made out of?

Answer 14

plants and animals that died and got trapped in mud and rocks millions of years ago.

Question 15

Name the three fossil fuels

Answer 15

Oil, coal and natural gas.

Question 16

Are fossil fuels renewable? Why?

Answer 16

No. They take millions of years to form.

Question 17

What do the gases produced when fossil fuels are burnt cause?

Answer 17

Pollution and global warming

Question 18

Are fossil fuels cheap or expensive?

Answer 18

Are relatively cheap to obtain.

Question 19

What was the original source of energy for fossil fuels?

Answer 19

The sun. Plants got their energy from the sun and animals got their energy from eating plants, which got their energy from sun.

Question 20

Is nuclear fuel renewable? Why?

Answer 20

Is non-renewable. Nuclear power stations produce dangerous waste materials.

Question 21

Is electricity a fuel?

Answer 21

No. It has to be generated by using other energy sources.

Question 22

What can be done to reduce the usage of fossil fuels?

Answer 22

• Walking or cycling instead of using the car.
• Using public transport instead of cars.
• Keeping our houses cooler or keeping us warm with more clothes instead of heating.

Question 23

Name the 7 types of renewable energy

Answer 23

• Solar
• Wind
• Tidal
• Wave
• Biofuels
• Geothermal
• Hydroelectricity

Question 24

What are the advantages of using renewable energy resources?

Answer 24

• Do not produce harmful gases or contribute to pollution.
• Will not run out

Question 25

What are the disadvantages of using renewable energy resources?

Answer 25

• Are not always availabe (i.e. solar energy is only available when there’s sun)
• Are often more expensive than fossil fuels.

Question 26

Describe the availability of hydroelectricity, geothermal energy and biofuels

Answer 26

Are pretty much always available.

Question 27

Describe the availability of tidal power

Answer 27

Is not always available, but we can predict when it will be.

Question 28

Describe the availability of solar, wind and wave energy

Answer 28

Not always available

Question 29

What are the only types of power that do not depend originally from the sun?

Answer 29

Geothermal, Nuclear and tidal power.