SP3

Question 1

What are the different examples of energy stores?

Answer 1

• Chemical energy
• Kinetic energy
• Thermal energy
• Elastic potential energy
• Gravitational potential energy
• Atomic/nuclear energy

Question 2

What is the law of conservation of energy?

Answer 2

Energy cannot be created or destroyed, it can only be transferred from one store to another.

Question 3

What unit is used for measuring energy?

Answer 3

Joules (J).

Question 4

How do we calculate the efficiency of a machine at transferring energy?

Answer 4

‎ Useful energy transferred by the device
Efficiency = __________________________________________
‎ Total energy supplied to the device

Question 5

What happens during conduction?

Answer 5

Vibrations are passed on between particles in a solid.

Question 6

What happens during convection?

Answer 6

Part of a fluid that is warmer than the rest rises and sets up a convection current.

Question 7

In which process can energy be transferred through a vacuum?

Answer 7

Radiation.

Question 8

What is gravitational potential energy?

Answer 8

The energy that is stored because of an object’s position in a gravitational field.

Question 9

How do we calculate the change in gravitational potential energy?

Answer 9

Change in gravitational potential energy (J) = mass (kg) ‎× gravitational field strength (N/kg) × change in vertical height (m)

ΔGPE = m × g × Δh