Energy Resources and Energy Transfers

Question 1

Suggest one energy store that energy is transferred to when energy is wasted by a crane?

Answer 1

Thermal

Question 2

Suggest one way in which energy is wasted by a fan?

Answer 2

The heating of the fan

Question 3

Where is energy transferred from when a skydiver is falling from an aeroplane?

Answer 3

Gravitational potential energy store

Question 4

Where is energy transferred from when a substance is undergoing a nuclear reaction

Answer 4

Nuclear energy store

Question 5

Where is energy transferred from when a stretched spring returns to its original shape

Answer 5

Elastic Potential Energy store

Question 6

Where is energy transferred from when a piece of coal burns

Answer 6

Chemical Energy store

Question 7

How is energy transferred from the mains to the kettle

Answer 7

Electrically

Question 8

State the principle of conservation of energy

Answer 8

Energy can’t be created or destroyed only transferred

Question 9

Efficiency equation

Answer 9

Efficiency = Useful output energy transfer/ Total input energy transfer

Question 10

What is power

Answer 10

Power is the rate of doing work. The units are Watts.

Question 11

Why is the efficiency of an appliance always less than 100%

Answer 11

Some energy is always dissipated, so less than 100% of the input energy transfer is transferred usefully.

Question 12

What is the equation linking power, work done and time?

Answer 12

Power = work done / time

Question 13

Name two ways in which flasks will transfer energy by heating to the gel surrounding them

Answer 13

Conduction + Radiation

Question 14

Which of the following is not an example of convection?

the heating of a large room by a radiator

the heating of water in a kettle

the transfer of energy by heating through a copper pan

hot air rising up

Answer 14

C - the transfer of energy by heating through a copper pan

Question 15

What is the definition of power

Answer 15

The rate of energy transfer

Question 16

What is the equation that links work done, force applied and distance moved in the direction of the force?

Answer 16

W = F x d

Question 17

When hot water is poured into a Leslie cube, what side would feel the warmest when you place your hand in front of the surface of it.

Answer 17

Matt Black

Question 18

When hot water is poured into a Leslie cube, what side would feel the coolest when you place your hand in front of the surface of it.

Answer 18

Matt white

Question 19

Name two methods of energy transfer

Answer 19

Mechanically (by a force doing work)
Electrically (work done by when a current flows)
Heating
Radiation

Question 20

State the equation linking energy in an objects kinetic energy store with mass and speed.

Answer 20

Kinetic energy =
0.5 x mass x (speed)^2 / Ek = 0.5 x mv^2

Question 21

When a ball is thrown upwards, how does the way energy is stored change?

Answer 21

• Transferred from the chemical stores of the arm and the ball (and the gravitational energy store of the ball)
• Once it’s released, energy is transferred from the kinetic energy store of the ball to its GPE store.