CHAPTER 2

Question 1

How does loft insulation work

Answer 1

Reduces energy lost through roof by conduction

Question 2

What is a good insulator

Answer 2

Fibreglass

Question 3

How does cavity wall insulation work

Answer 3

Reduces energy lost through outer wall of house

Insulation fills the cavity so heat can’t escape easily

Question 4

How does putting aluminium foil between a radiator and the wall help

Answer 4

Foil reflects heat away from wall

Question 5

How do double glazed windows help

Answer 5

Reduces energy lost through conduction

Two panes of glass with vacuum between

Question 6

Ways to insulate house

Answer 6

Loft insulation 
Cavity wall insulation 
Double glazed windows 
Aluminium behind radiators 
Thicker bricks on external walls

Question 7

When a substance is heated what does the temperature rise depend on

Answer 7

Amount of energy supplies to it
Mass of substance
What the substance is

Question 8

What is the specific heat capacity of a substance

Answer 8

The energy needed to raise temperature of 1kg of the substance by 1 degree

Question 9

What is the equation for energy transferred using mass SHC and temperature change

Answer 9

energy transferred = mass x SHC x temperature change

Question 10

When does the temperature of an object increase

Answer 10

When it absorbs more radiation than it emits

Question 11

What does the temperature of the earth depend on

Answer 11

Absorption and emission of infrared radiation

Question 12

What do all objects emit

Answer 12

Infrared radiation

Question 13

The higher the temperature of an object

Answer 13

The more infrared radiation it emits

Question 14

What is a perfect black body

Answer 14

An object that absorbs all the radiation that hits it

Question 15

How does cavity wall insulation work

Answer 15

Reduces energy lost through outer walls of house

Insulation fills cavity so heat can’t escape easily

Question 16

How does aluminium foil between a radiator and wall help

Answer 16

Foil reflects heat away from wall

Question 17

How do double glazed windows help

Answer 17

Reduces energy lost through conduction

Two lanes of glass with vacuum between

Question 18

When a substance is heated what does the temperature rise depend on

Answer 18

Amount of energy supplied to it
Mass of the substance
What the substance is

Question 19

What do all objects emit

Answer 19

Infrared radiation

Question 20

The higher the temperature of an object…

Answer 20

The more infrared radiation it emits

Question 21

What is a conductor

Answer 21

Something that lets energy travel through it

Question 22

A good insulator must have

Answer 22

Low thermal conductivity

Question 23

What is conduction

Answer 23

When vibrating particles transfer energy to neighbouring particles

Question 24

What is the thermal conductivity of a material

Answer 24

How much energy it can transfer per second by conduction

Question 25

What does the energy transfer through a layer of material depend on

Answer 25

Temperature difference Thermal conductivity Thickness

Question 26

Why does the color of an object change as it is heated

Answer 26

It emits more radiation at shorter wavelengths

Question 27

What type of radiation does earth emit

Answer 27

Long wave

Question 28

How to reduce energy transfer

Answer 28

The thermal conductivity of the material should be as low as possible The thickness should the insulator should be as big as possible

Question 29

What will an object with a constant temperature do

Answer 29

Emit radiation across a continuous range of wavelengths

Question 30

What do greenhouse gases do

Answer 30

it absorbs long wave lengths from earth to stop it reflecting into space

Question 31

How do solar panels function

Answer 31

Absorbs infrared radiation from the sun to generate electricity or heat water