Section 4 - Energy Resources and Energy Transfer

Question 1

What is the principle of the conservation of energy?

Answer 1

Energy can never be created nor destroyed - it’s only ever transferred from one form to another

e. g. chemical energy in food to kinetic energy in animals
e. g. electrical energy to light energy in lamps

Question 2

What is the equation for EFFICIENCY?

Answer 2

Efficiency = Useful Energy Output / Total Energy Input

Question 3

What does it mean if an object is efficient?

Answer 3

A lot of its released energy is in a useful form

Question 4

What are the three ways in which heat is transferred?

Answer 4

Conduction, Convection and Radiation

Question 5

What is conduction?

Answer 5

Conduction is when energy is passed from one particle to another via contact.

Question 6

What is convection?

Answer 6

Convection is when particles with energy rises. The space that they leave is filled by other particles. If the source of energy continues, these new particles will also gain energy. Then, they will rise and the process is repeated.

Question 7

What is radiation?

Answer 7

Radiation is when heat is transferred as infrared waves. These waves can travel through space and be conducted or reflected

Question 8

What role does convection have in everyday life?

Answer 8

A radiator in a room will be able to heat a whole room, as hot air will rise away from it creating a current of cool air to be heated

Question 9

How can we reduce energy transfers from buildings and the human body?

Answer 9

Insulation can be used to reduce heat transfer.

For example, a house can have double glazed windows and thick curtains

Question 10

What is the equation for WORK DONE?

Answer 10

Work Done = Force x Distance Moved

Question 11

What does work done equal to?

Answer 11

Work Done is equal to Energy Transferred

Question 12

What is the equation for GRAVITATIONAL POTENTIAL ENERGY?

Answer 12

GPE = mass x gravitational field strength x height

Question 13

What is the equation for KINETIC ENERGY?

Answer 13

KE = 1/2 x mass x velocity^2

Question 14

How is kinetic energy and gravitational potential energy linked?

Answer 14

When an object falls, it reduces gravitational potential energy and gains kinetic energy.

Kinetic Energy Gained = GPE Lost

Question 15

What is power?

Answer 15

Power is the rate of transfer of energy or the rate of doing work

Question 16

What is the equation for POWER?

Answer 16

Power = Work Done / Time Taken

Question 17

Describe the energy transfers involved in generating electricity using wind

Answer 17

Kinetic energy (wind) turns a turbine, which turns a generator. This produces electrical energy.

Question 18

Describe the energy transfers involved in generating electricity using water

Answer 18

Kinetic energy (water) turns a turbine, which turns a generator. This produces electrical energy.

Question 19

Describe the energy transfers involved in generating electricity using geothermal resources

Answer 19

Thermal energy heats water. The water turns into steam and the steam turns a turbine, which then has kinetic energy. The turbine turns a generator, which produces electrical energy

Question 20

Describe the energy transfers involved in generating electricity using solar heating systems

Answer 20

Solar heating systems convert light energy from the sun to thermal energy in water (it heats it up)

Question 21

Describe the energy transfers involved in generating electricity using solar cells

Answer 21

Solar cells convert light energy from the sun into electrical energy

Question 22

Describe the energy transfers involved in generating electricity using fossil fuels

Answer 22

Chemical energy is burnt to form heat energy. This energy into heat energy in water. This turns into kinetic energy in a turbine, which turns into electrical energy in a generator.

Question 23

Describe the energy transfers involved in generating electricity using nuclear power

Answer 23

Kinetic energy in uranium is converted to heat energy in water. This heat energy turns a turbine (KE), which produces electrical energy in a generator