Energy

Question 1

What is the definition for the conservation for energy?

Answer 1

Energy cannot be created or destroyed, merely transferred from one form to another.

Question 2

What does all energy end up as?

Answer 2

Thermal energy.

Question 3

What is the unit for energy?

Answer 3

Joule, J.

Question 4

How much energy is needed to lift an apple vertically up 1m?

Answer 4

1J.

Question 5

What are the different forms of energy?

Answer 5

Chemical energy
Electrical energy
Thermal energy
Sound energy
Light energy
Magnetic energy
Strain energy
Kinetic energy
Gravitational potential energy

Question 6

What is the energy transfer diagram for a wind turbine?

Answer 6

E in:

Kinetic energy

E out:

Electrical energy
Sound energy
Thermal energy

Question 7

What is the energy transfer diagram for a hydroelectric power station?

Answer 7

E in:

Gravitational potential energy

E out:

Electrical energy
Thermal energy
Kinetic energy
Sound energy

Question 8

What is the energy transfer diagram for an electric fan?

Answer 8

E in:

Electrical energy

E out:

Thermal energy
Kinetic energy
Sound energy

Question 9

What is the energy transfer diagram for a speaker?

Answer 9

E in:

Chemical energy

E out:

Thermal energy
Sound energy
Kinetic energy

Question 10

What is the energy transfer diagram for a TV?

Answer 10

E in:

Electrical energy

E out:

Light energy
Sound energy
Thermal energy

Question 11

What is the energy transfer diagram for a radio?

Answer 11

E in:

Chemical energy

E out:

Sound energy
Thermal energy

Question 12

What is the energy transfer diagram for a car engine?

Answer 12

E in:

Chemical energy

E out:

Kinetic energy
Sound energy
Thermal energy

Question 13

How can all energy transfers that are associated with a device be represented?

Answer 13

By a Sankey diagram

Question 14

How does a Sankey diagram represent all output energies?

Answer 14

Using arrows.

Thickness of each arrow proportional to amount of energy involved at that stage.

Question 15

What is the definition for renewable energy?

Answer 15

Energy that is collected from resources that will never run out or which are naturally replenished within a human lifetime.

Question 16

What are the types of renewable energy?

Answer 16

Sunlight
Wind
Hydroelectric
Tidal
Wave
Wood
Geothermal

Question 17

What are the 2 types of sunlight energy farming?

Answer 17

Solar PV - produces electricity
Solar thermal - produces hot water

Question 18

What are the positives of sunlight energy.

Answer 18

Free.
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.

Question 19

What are the negatives of sunlight energy.

Answer 19

Intermittent.
Low values near each pole.

Question 20

What are the positives of wind energy.

Answer 20

Free.
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.

Question 21

What are the negatives of wind energy.

Answer 21

Intermittent.
High initial costs.

Question 22

What are the positives of hydroelectric energy.

Answer 22

Free electric.
No GHG emitted.
Reduce energy bills.
Develop a revenue stream.
Can control when power is produced.

Question 23

What are the negatives of hydroelectric energy.

Answer 23

Need correct topography of ground.
Huge initial investment.

Question 24

What are the positives of tidal energy.

Answer 24

Free electric.
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.
Predictable power output.

Question 25

What are the negatives of tidal energy.

Answer 25

Need correct topography of ground. Large initial investment.

Question 26

What are the positives of wave energy.

Answer 26

Free electric. No GHG emitted. Will not run out. Develop a revenue stream. Predictable power output.

Question 27

What are the negatives of wave energy.

Answer 27

Oil spills. Habitat destruction. Visual impact.

Question 28

What are the positives of wood energy.

Answer 28

Will not run out (if replanted). Can be stored for future use. Can be grown locally.

Question 29

What are the negatives of wood energy.

Answer 29

Overuse. Does give out CO2.

Question 30

What are the positives of geothermal energy.

Answer 30

Free. No GHG emissions. Reduce bills. Hot water can be stored.

Question 31

What are the negatives of geothermal energy?

Answer 31

Expensive to set up. Leaks into ground.

Question 32

What is efficiency?

Answer 32

Measure of how good a device is at changing energy from one form to another.

Question 33

How is the efficiency of a device related to energy wasted?

Answer 33

The more efficient a device is the less energy is wasted.

Question 34

What is the equation for energy efficiency?

Answer 34

Energy efficiency = useful output of energy / total input energy OR eff = E out / E in

Question 35

What are the quantities involved in eff = E out / E in?

Answer 35

Useful energy measured in joules (J). Total energy measured in joules (J). Energy efficiency has not units.

Question 36

How is energy efficiency measured?

Answer 36

Number between 0 to 1, can be converted into percentage.

Question 37

What is the link between work done and energy transferred?

Answer 37

Work done = energy transferred

Question 38

What is the equation for work done.

Answer 38

Work done = force x distance moved OR Wd = F x d

Question 39

What are the quantities involved in Wd = F x d?

Answer 39

Force measured in newtons (N). Distance moved measured in metres (m). Work done measured in joules (J).

Question 40

What is power?

Answer 40

Rate of doing work or rate of transferring energy.

Question 41

What is the equation for power?

Answer 41

Power = work done / time taken OR P = Wd / t / P = E / t

Question 42

What are the quantities involved in P = Wd / t?

Answer 42

Work done measured in joules (J). Time measured in seconds (s). Power measured in watts (W).

Question 43

What is kinetic energy?

Answer 43

The energy an object has because it is moving.

Question 44

What is the equation for kinetic energy?

Answer 44

KE = 1/2 x mass x velocity2^ OR KE = 1/2 x m x v2^

Question 45

What are the quantities involved in KE = 1/2 x m x v2^?

Answer 45

Mass measured in kilograms (kg). Velocity measured in metres per second (m/s). KE measured in joules (J).

Question 46

What is the equation for gravitational potential energy?

Answer 46

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

Question 47

What are the quantities involved in GPE = m x g x h?

Answer 47

Mass measured in kilograms (kg). Gravitational field strength measured in Newton’s per kilogram (N/kg), usually taken as 10N/kg on Earth. Height measured in metres (m). GPE measured in joules (J).