Energy Transfers, Work & Power

Question 1

What are 8 examples of energy stores?

Answer 1

Chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic and nuclear

Question 2

What are 4 examples of energy transfers?

Answer 2

Mechanically, electrically, by heating, by radiation (light/sound)

Question 3

What is a magnetic energy story?

Answer 3

Energy stored when repelling poles are pushed together or when attracting poles have been pulled apart

Question 4

What is a thermal energy store?

Answer 4

Total kinetic and potential energy of particles in an object (eg. Vibrations)

Question 5

What is a chemical energy store?

Answer 5

The energy stored in chemical bonds (eg. Between molecules)

Question 6

What is kinetic energy store?

Answer 6

The energy of a moving object

Question 7

What is an Electrostatic energy store?

Answer 7

The energy stored when repelling charges have been moved closer together OR attracting forces, pulled apart

Question 8

What is the energy store of elastic potential?

Answer 8

The energy stored when an object is stretch or squashed

Question 9

What is the energy store of gravitational potential?

Answer 9

The energy of an object at height

Question 10

What is the energy store for nuclear energy?

Answer 10

The energy stored in the nucleus of an atom

Question 11

What is the principle of the conservation of energy?

Answer 11

Energy is neither created or destroyed but it can transform from one type to another

Question 12

What is the principle of the conservation of energy?

Answer 12

Energy is neither created or destroyed but it can transform from one type to another

Question 13

What is the relationship between efficiency, useful energy output and total energy output?

Answer 13

Efficiency = (useful energy output / total energy output) x 100%

Question 14

What do Sankey diagrams help us see?

Answer 14

What happens to the energy input in a system and how much of the energy was used and wasted

Question 15

How do we read Sankey diagrams?

Answer 15

The width of the arrow is proportional to the amount of energy (eg. 70 Joules = 7cm)

Question 16

What is the relationship between work, force and distance moved in the direction of that force?

Answer 16

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

Question 17

What is significant about the work done and the energy transferred?

Answer 17

They are equal

Question 18

What is the relationship between Gravitational potential energy, mass, g and height?

Answer 18

Gravitational potential energy = mass x g x height
GPE = m x g x h

Question 19

What is the relationship between Gravitational potential energy, mass, g and height?

Answer 19

Gravitational potential energy = mass x g x height
GPE = m x g x h

Question 20

What is the relationship between Gravitational potential energy, mass, g and height?

Answer 20

Gravitational potential energy = mass x g x height
GPE = m x g x h

Question 21

What is the relationship between kinetic energy, mass and speed?

Answer 21

Kinetic energy = 1/2 x mass x (speed)2

KE = 1/2 x m x (v)2

Question 22

How does the conservation of energy produce a link between potential energy, kinetic energy and work?

Answer 22

When a falling object hits ground and stops, the kinetic energy is transferred to the ground in form of work done dropping it (eg. Throwing).

Question 23

What is power?

Answer 23

The rate of transfer of energy or the rate of doing work

Question 24

What is the relationship between power, work done (energy transferred) and time taken?

Answer 24

Power = work done / time taken
p =w/t