Energy

Question 1

What are the energy stores?

Answer 1

chemical, kinetic, elastic potential, gravitational potential, thermal, magnetic, electrostatic, nuclear

Question 2

What are the energy transfers?

Answer 2

mechanically, electrically, by heating, by radiation (light and sound)

Question 3

What is the principle of the conservation of energy?

Answer 3

Energy is not created nor destroyed.

Question 4

What is the equation for efficiency?

Answer 4

(useful energy output/total energy output) x 100

(useful/total) x 100

Question 5

What is the equation for work done?

Answer 5

W = F x d
work done = force x distance moved

Question 6

Work done is equal to….

Answer 6

Energy transferred.

Question 7

What is the equation for GPE (gravitational potential energy)?

Answer 7

Eₚ=m x g x h
GPE = mass x gravitational field strength x height

Question 8

What is the equation for KE (kinetic energy)?

Answer 8

Eₖ = 1/2 x m x v²
KE = 1/2 x mass x velocity²

Question 9

What is power?

Answer 9

Rate of energy transfer, or rate of work.

Question 10

What is the equation for power?

Answer 10

P = E/t (PET)
or
P = W/t

power = energy transferred/time
or
power = work/time

Question 11

What are the energy transfers involved with generating electricity using: wind?

Answer 11

Wind’s kinetic energy rotates the rotor blades. The generator converts the turbine’s mechanical energy into electricity.

Question 12

What are the energy transfers involved with generating electricity using: water?

Answer 12

As the water flows down through the dam its kinetic energy is used to turn a turbine. The generator converts the turbine’s mechanical energy into electricity.

Question 13

What are the energy transfers involved with generating electricity using: geothermal resources?

Answer 13

Geothermal power plants use steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth’s surface. The steam rotates a turbine that activates a generator, which produces electricity.

Question 14

What are the energy transfers involved with generating electricity using: solar heating systems?

Answer 14

Thermal energy (from sun) from water -> kinetic energy (steam, evaporation of water), turns turbines -> electrical energy, in the generator.

Question 15

What are the energy transfers involved with generating electricity using: solar cells?

Answer 15

Thermal energy (from sun) —> electrical energy, solar cells.

Question 16

What are the energy transfers involved with generating electricity using: fossil fuels?

Answer 16

chemical energy stored in the fuels, to heat energy as it burns which is converted to kinetic energy as it drives large turbines and finally this is converted to electrical energy

Question 17

What are the energy transfers involved with generating electricity using: nuclear power?

Answer 17

nuclear reaction releases heat – nuclear energy is converted to heat energy: heat is used to change water into steam in the boiler. the steam drives the turbine (heat to kinetic energy) this drives the generator to produce electricity – kinetic to electrical energy.