P2 Heat Transfers

Question 1

How does heat move along a metal bar

Answer 1

Conduction

Question 2

What are the best conductors of energy

Answer 2

Metal

Question 3

What is conduction

Answer 3

Collisions between fast moving to slow moving electrons. The particles nearer to the heat sorce move quickest.

Question 4

What materials are the best insulators

Answer 4

Wool and fibreglass

Question 5

Relationship between thermal conductivity and rate of energy transfer in a material

Answer 5

The higher the thermal conductivity the higher the rate of energy transfer

Question 6

What is specific heat capacity

Answer 6

The thermal energy required to raise the temperature of a body of mass 1kg by 1K

Question 7

Equation for energy transferred

Answer 7

Energy transferred= mass x specific heat capacity x temperature change

Question 8

Equation for specific heat capacity

Answer 8

Change in energy/ mass x change in temperature

Question 9

What happens in a convection current

Answer 9

Colder water is dense and falls it then gets heated and becomes less dense and therefore rises. As it gets further the temperature decreases and the cycle repeats

Question 10

Ways to reduce the rate of energy transfer

Answer 10

-loft insulation
-double glazed windows
-cavity wall insulation