Work Done By A Force

Question 1

Define work

Answer 1

Whenever energy is transferred from one store to another

Question 2

Define mechanical work

Answer 2

Involves using a force to move an object

Question 3

Define electrical work

Answer 3

Involves a current transferring energy

Question 4

What happens when a car brakes

Answer 4

Brake presses against wheel of car
= creates friction between brake and wheel
= kinetic energy transferred to thermal energy store in brakes
= temp of brakes increase

Question 5

Factors effecting cooling of a building

Answer 5

Thermal conductivity of material
= the higher the rate of energy transfer by conduction across material
Build house with thick walls

Question 6

How to prevent thermal energy lost in homes

Answer 6

• Builders pack cavity between brick with an insulating material which has a very low thermal conductivity
  = less thermal energy escapes walls
• Use double glazed windows with low thermal conductivity
• Loft insulation