Energy, fossil fuels, and renewable energy

Question 1

Define energy and state its units. (2)

Answer 1

Energy is the ability to do work (1) It is measured in Joules. (1)

Question 2

List the 8 main forms of energy and briefly explain them. (2)

Answer 2

Kinetic energy
Heat energy
Light energy
Chemical energy
Elastic Potential energy
Gravitational potential energy
Electrical energy
Sound energy
Nuclear energy (1)
(Anything sensible for part 2) (1).

Question 3

State the Law of Conservation of Energy. (3)

Answer 3

Energy can neither be created (1) nor destroyed (1), but only changed from one form to another. (1)

Question 4

Show how energy can be transferred from one form to
another. (8)

Answer 4

Mechanically - By the action of a force.
Electrically - By an electrical current.
Radiation - By Light waves or Sound waves.
Heating - By conduction, convection or radiation.

Question 5

Distinguish between and describe; conduction,
convection, and radiation. (3)

Answer 5

Conduction is the flow of heat energy from a region of high temperature to a region of low temperature without overall movement of the material itself. (1)

Convection is the flow of heat energy from a region of high temperature to a region of low temperature by movement of a fluid. Convection only occurs in fluids (liquids and gases). (1)

Radiation is the transfer of heat energy from a region of high temperature to a region of low temperature by infrared radiation. (1)

Question 6

List examples of renewable energy and describe how they can benefit from the environment. (6)

Answer 6

Any three of: wind power, wave power, hydroelectric power, solar power and in the future, tidal power. (3)
These renewable sources of energy are much cleaner to use than fossil fuels because they do not produce harmful gases (1) that cause pollution (1) and climate change. (1)

Question 7

Distinguish between a renewable and non-renewable
source of energy. (2)

Answer 7

Non-renewable energy includes coal, gas and oil. Machines all get the energy to move from burning fossil fuels to release the energy they contain. Once fossil fuels are burned they are gone - that’s why they are non-renewable. (1)

Renewable energy includes solar, hydro and wind energy. When the wind (for example) moves the blades on a wind turbine this movement can be converted into electrical energy that we can use. The wind is not used up - that’s why it is renewable. (1)

Question 8

Define a fossil fuel, how it is formed and give an example. (3)

Answer 8

Fossil fuels are the remains of creatures and plants that lived millions of years ago. (1)
1. Both oil and gas come from layers of dead marine organisms.
2. When they died, their bodies fell to the bottom of the sea. Over millions of years, layers of mud and rock built up over them which put them under massive pressure.
3. This, together with the geothermal heat from the earth’s mantle, changed them into oil and gas. (1)
Gas, coal and oil are fossil fuels. (1)