Unit 1 - Energy

Question 1

What is energy?

Answer 1

Cannot be created or destroyed only transferred. Whenever anything happens energy changes between forms.

Question 2

How do you calculate kinetic energy? What goes on top of the triangle?

Answer 2

Kinetic energy = 0.5 x mass x velocity^2. Kinetic energy.

Question 3

What is energy measured in? What is mass measured in? What is the velocity measured in?

Answer 3

Joules (J). Kilograms (kg). Metres per second (m/s).

Question 4

If a spring is stretched what does it store?

Answer 4

Elastic potential energy.

Question 5

How can you increase the amount of elastic potential energy stored in a spring?

Answer 5

Increase the extension of the spring or increase the spring constant.

Question 6

What do the springs store?

Answer 6

Elastic potential energy.

Question 7

What is gravitational field strength?

Answer 7

The pull of gravity on each kilogram.

Question 8

What is potential energy?

Answer 8

The energy which is stored in an object because of its position. Either in a spring because its stretched or in an object that’s been lifted.

Question 9

How do you calculate elastic potential energy? What is on top of the triangle?

Answer 9

Elastic potential energy = 0.5 x spring constant x extension^2. Epe.

Question 10

What is epe measured in? What is spring constant measure in? what is extension measured in?

Answer 10

Joules (J). Newtons per metre (N/m). Metres (m).

Question 11

What is spring constant?

Answer 11

How much an object will stretch by. If you need a lot of force it has a higher spring constant, less is lower.

Question 12

How do you calculate gravitational potential energy? What is on top of the triangle?

Answer 12

Gravitational potential energy = mass x gravitational field strength x height. Gpe.

Question 13

What is gpe measured in? What is mass measured in? What is gfs measured in? What is height/extension measured in?

Answer 13

Joules (J). Kilograms (kg). Newtons per kilogram (N/kg). Metres(m).

Question 14

What does a ball have more of if it is dropped from a greater height? As it falls what decreases? What increases? What is GPE transferred to?

Answer 14

Gravitational potential energy. GPE. KE. KE.

Question 15

What is dissipated energy?

Answer 15

The energy which is wasted - not transferred usefully to surroundings.

Question 16

What is specific heat capacity? What does the amount of energy needed to change the temperature depend on? Why is water a very useful way of transferring large amounts of thermal energy? Give example. What can water absorb a lot of? Give example.

Answer 16

A measure of how much energy is required to raise the temperature of a 1kg substance by 1*C. Mass, material and temperature change. Water can release a lot of energy without a large temperature decrease. Central heating system. Thermal energy from a hot object so can cool many car engines.

Question 17

What is power? What is it measured in? What is it equal to?

Answer 17

The rate at which energy is transferred or the rate that work is done. Watts. One joule transferred every second.

Question 18

How do you calculate power? What is on top of the triangle?

Answer 18

Power = energy transferred/time. Energy transferred.

Question 19

What is power measured in? What is energy measured in? What is time measured in?

Answer 19

Watts (W). Joules (J). Seconds (s).

Question 20

What does work done and frictional forces causes?

Answer 20

Energy transfer.

Question 21

What can be used to reduce friction?

Answer 21

Lubrication - oil.

Question 22

How can you insulate an object? What will this do?

Answer 22

Wrap thermal insulation around and object to stop it losing heat. Thicker material is better insulation.

Question 23

What is a thermal image? What is it taken using?

Answer 23

Thermogram. Infared radiation.

Question 24

What is energy efficient?

Answer 24

When less energy is wasted so the transferred energy is used ruefully. Less dissipated.

Question 25

How do you calculate efficiency? What is on top of the triangle?

Answer 25

Efficiency = useful output energy / total input energy. Useful output energy.

Question 26

What is efficiency measured in? What is energy measured in? What is power measured in?

Answer 26

Percentage or decimal. Joules (J). Watts (W).

Question 27

In the practical with different insulating materials, which should have been the best? Why? Which should lose the most heat?

Answer 27

Bubble wrap because it is the thickest and contains air which is a good insulator. One with no material as it has no insulator.

Question 28

Which material should help maintain heat? Why? Which shouldn’t maintain heat? Why?

Answer 28

Aluminium foil as it reflects the heat back. Newspaper, as it is dark so, emits the heat.

Question 29

Name the energy resources.

Answer 29

Solar, wind, coal, oil, gas, nuclear, tidal, wave, hydroelectric, geothermal, biofuel.

Question 30

Which energy resources are renewable?

Answer 30

Waves, tidal, hydroelectric, geothermal, solar, wind, biofuels.

Question 31

Which energy resources are non-renewable?

Answer 31

Nuclear, gas, oil, coal.

Question 32

Which energy resources are reliable?

Answer 32

Tidal, hydroelectric, geothermal, oil, gas, coal, nuclear, biofuels.

Question 33

Which energy resources are unreliable?

Answer 33

Wind, solar, waves.