Conservation And Dissipation of Energy

Question 1

What is the law of the conservation of energy

Answer 1

Energy cannot be created or destroyed only transferred from one store to another

Question 1

Name ways of reducing dissipation of energy (unwanted energy transfers)

Answer 1

Lubrication

Thermal Insulation

Question 2

What is the relationship between thermal conductivity and the rate of energy transfer

Answer 2

They are proportional- the higher the thermal conductivity of a material, the higher the rate of energy transfer by conduction across the material

Question 3

How is the rate of cooling of a building affected by the thickness of its walls

Answer 3

The thicker the walls, the slower the rate of cooling,

if the walls are thin the rate of cooling will increase

Question 4

How is the rate of cooling of a building affected by the thermal conductivity of its walls?

Answer 4

The higher the thermal conductivity the faster the rate of cooling of the builidng,

if the walls have a low thermal energy and are goo insulators, the rate of cooling will reduce

Question 5

What does energy/power efficient mean?

Answer 5

A higher proportion of the total energy/power input is usefully transferred as useful energy/power