Energy

Question 1

What is gravitational potential energy?

Answer 1

The energy stored in an object due to its position above the Earth’s surface.

Question 2

What is the equation for gravitational potential energy?

Answer 2

Ep = mass X gravitational field strength X height

Question 3

What is the gravitational field strength on Earth?

Answer 3

9.8

Question 4

What things can a house have to make it more energy efficient?

Answer 4

Cavity wall insulation, double glazing, loft insulation, carpets, curtains, draught excluders, jacket around hot water tank.

Question 5

What is wasted energy?

Answer 5

Any energy that comes out of a situation that we didn’t intend to be there.

Question 6

What happens to wasted energy?

Answer 6

It dissipates into the surroundings (it spreads out so much that it can’t be collected but it’s still there).

Question 7

What is the equation for kinetic energy?

Answer 7

½ X mass X velocity²

Question 8

What is the equation for elastic potential energy?

Answer 8

½ X spring constant X extension²

Question 9

Change in thermal energy = ?

Answer 9

Change in thermal energy = mass X specific heat capacity X change in temperature

Question 10

What are all the forms of energy?

Answer 10

Gravitational potential, electrical, elastic potential, kinetic, sound, light, nuclear, chemical, heat (thermal)

Question 11

Power = ?

Answer 11

Power = energy ÷ time

Question 12

Efficiency = ?

Answer 12

Efficiency = useful energy out ÷ total energy in (×100)

Question 13

Change in thermal energy = ?

Answer 13

Change in thermal energy = mass X specific heat capacity X change in temperature

Question 14

Power = ?

Answer 14

Power = work done ÷ time

Question 15

What is power?

Answer 15

The rate at which energy is transferred or the rate at which work is done.

Question 16

What does low thermal conductivity mean?

Answer 16

It means that heat energy is transferred at a lower rate.