heat transfer

Question 1

name three types of heat transfer

Answer 1

Convection
Conduction
Radiation

Question 2

What is RADIATION

Answer 2

radiation is the heat energy emitted (given off) by an object

Question 3

name the main source of radiation

Answer 3

the sun

Question 4

name three things that emit heat radiation

Answer 4

fire
kettle
humans
toaster
cooker
the list is huge!!!!

Question 5

how does the radiation from the sun help us

Answer 5

it provides daylight
it provides warmth for our planet
we can capture the suns energy (solar energy) and turn it into electricity

Question 6

a dark coloured surface absorbs radiation better than a light surface
true or false

Answer 6

true - a dark surface absorbs more energy than a light one

Question 7

a shiny surface absorbs radiation better than a matt surface
true or false

Answer 7

False - a matt surface absorbs more energy

Question 8

which reflects more energy a shiny surface or a matt surface

Answer 8

a shiny surface

Question 9

does a smooth surface absorb/reflect more energy than a bumpy surface

Answer 9

yes the bumpy surface has a larger surface area to absorb/reflect energy

Question 10

what do we mean by the term CONDUCTION

Answer 10

conduction is where heat energy is passed from atom to another

Question 11

plastic and wood are good conductors

true or false

Answer 11

False - plastic and wood are poor conductors of heat

Question 12

are metals good conductors of heat

Answer 12

Yes - a metal rod heated at one end will eventually get hot at the other end

Question 13

why do pans and cooking equipment have plastic or wooden handles

Answer 13

to stop you from burning your fingers and hands. the wood and plastic does not conduct the heat from the pan to your hand

Question 14

why are pans made of metal

Answer 14

so that the pan conducts heat from the cooker to the food

Question 15

what does CONVECTION mean

Answer 15

convection is the process where hot fluids rise and cold fluids fall

Question 16

does convection take place in solids liquids or gases

Answer 16

it happens in liquids and gases where the molecules are able to move

Question 17

how does convection work

Answer 17

in a pan of water on a cooker the water near the heat (the bottom) warms up and moves to the top of the pan.
cold water moves in behind it and gets warm. this produces a convection current

Question 18

how do we use convection in our homes

Answer 18

to heat the air in our rooms - the radiator or fire warms the air which rises and then cold air moves in behind and gets warmed up
to heat our water
to cook food
to boil the kettle

Question 19

what do we mean by the term insulator

Answer 19

this is something we use to prevent heat loss from a heat source

Question 20

name some ways we use insulation

Answer 20

to stop heat loss from the roof - loft insulation
to stop hot liquids from cooling too quickly - flask
to stop cold liquids getting hot - flask
to stop heat loss from the walls - cavity wall insulation