Energy topic 1 (transfers and stores)

Question 1

What is energy measured in?

Answer 1

Joules

Question 2

What is an energy store?

Answer 2

When an object stores energy as a certain type of energy which gives the object the potential to do something later.

Question 3

What is the principle of conservation of energy?

Answer 3

The principle of conservation of energy says that energy cannot be created or destroyed, only transferred from one store to another.

Question 4

What are the 11 types of Energy?
(Most, North, East, Kids, Hate, Learning, G, C, S, E, Everyday)

Answer 4

Magnetic
Nuclear
Electrical
Kinetic
Heat (thermal)
Light
Gravitational potential
Chemical
Sound
Elastic energy
Electrostatic

Question 5

What is magnetic energy?

Answer 5

Potential energy stored due to a magnetic field.

Question 6

What is nuclear energy?

Answer 6

Energy stored in the atoms of materials.

Question 7

What is electrical energy?

Answer 7

Energy carried by an electric current.

Question 8

What is kinetic energy?

Answer 8

Energy carried by moving objects.

Question 9

What is thermal energy?

Answer 9

Energy produced by hot objects.

Question 10

What is light energy?

Answer 10

Energy in the form of visible light.

Question 11

What is gravitational potential energy?

Answer 11

Energy stored by objects off of the ground.

Question 12

What is chemical energy?

Answer 12

Energy stored in food and fuel.

Question 13

What is sound energy?

Answer 13

Energy produced by vibrating objects.

Question 14

What is elastic potential energy?

Answer 14

Energy stored by stretched and squashed objects.

Question 15

What is electrostatic energy?

Answer 15

Energy stored due to the field set up around charged objects.

Question 16

What is internal energy?

Answer 16

The sum of kinetic and potential energy in a system, even when this energy is not visibly obvious (a still glass of water).

Question 17

Which colours cool the quickest and why?

Answer 17

Dark colours because black, matt surfaces are the best emitters/absorbers of infrared radiation.

Question 18

Why are light, shiny surfaces not good emitters of radiation?

Answer 18

They are good reflectors.

Question 19

Which objects emit thermal radiation?

Answer 19

All objects.

Question 20

What does a thermal camera do?

Answer 20

Detects thermal radiation and produces an image. Warm colours mean high levels of infrared and blue colours mean low levels.

Question 21

What do humans/reptiles look like on a thermal camera?

Answer 21

Humans are warm blooded so they give off more infrared radiation meaning warmer colours. Cold blooded reptiles show up as darker colours.

Question 22

What is infrared radiation?

Answer 22

A type of electromagnetic wave which transfers thermal energy, hotter objects emit more thermal energy.

Question 23

What does infrared radiation travel through?

Answer 23

All transparent states of matter. It travels through vacuums at the speed of light.

Question 24

Which objects are good/bad emitters/absorbers of infrared radiation.

Answer 24

Black objects are better. White/shiny objects are good reflectors so they reflect the infared.

Question 25

What is convection and what does it occur in?

Answer 25

The transfer of heat by the movement of particles in liquids and gases (fluids).

Question 26

Describe convection.

Answer 26

Heated particles gain energy and move faster, causing the fluid to become less dense and rise. The fluid cools down and loses energy, slows down, becomes denser and falls.

Question 27

What is the particles in a fluid rising and falling called?

Answer 27

Convection current.

Question 28

What does the sun create?

Answer 28

Large convection currents which cause wind.

Question 29

What is conduction?

Answer 29

Particles packed together vibrate and collide, transferring thermal energy. This only takes place in solids.

Question 30

Why are metals good conductors?

Answer 30

They have free electrons which move through the metal and pass on energy quicker.

Question 31

What is an insulator?

Answer 31

A bad conductor, such as rubber/plastic.

Question 32

Why are insulators bad conductors?

Answer 32

Contain air bubbles, particles in gases are far apart so they cannot easily collide and pass on vibrations.

Question 33

Why are two thin blankets better than one?

Answer 33

The air between them is a good insulator meaning you have an extra layer of insulation from the cold.

Question 34

Why do insulators have a low thermal conductivity?

Answer 34

They do not let thermal energy easily pass through them through conduction.

Question 35

What does a temperature change mean?

Answer 35

Large temp changes mean that it is a bad insulator as more heat is escaping, small temp change means it keeps the heat in.

Question 36

What happens when a heated substance starts cooling down?

Answer 36

The temp change is more rapid at the start as there is a big temp difference between the air and the substance.

Question 37

What do thicker materials do?

Answer 37

Lower the thermal conductivity.

Question 38

What happens to heat in a house?

Answer 38

Heat is lost through conduction in the windows, walls , roof and floor. Drafts enter houses through gaps in the windows and doors, heat is lost due to convection currents.

Question 39

What does home insulation do?

Answer 39

Reduces heat loss in a house.

Question 40

What is double glazing?

Answer 40

Gas or a vacuum trapped within two panes of glass to act as insulators.

Question 41

What is cavity wall/ loft insulation?

Answer 41

Foam or fibre glass containing lots of gas put in the walls to keep the house hot in the winter/cool in the summer.

Question 42

What does draught pooling do?

Answer 42

Cheap and effective way of reducing thermal transfers between the inside and outside of a house.

Question 43

What do curtains do?

Answer 43

Cuts down thermal energy loss through windows.

Question 44

What does aluminium foil behind radiators do?

Answer 44

The silvery surface reflects thermal energy back into the room.