Work done and energy transfers

4.5.2

What is the equation used to calculate work done ?

work done (joules) = force (newtons)   × distance (meters)

Does it mean if a force is said to do ‘work’?

When the force causes a displacement of the object through a distance

convert between newton-metres and joules.

1 joule = 1 newton - 1 metre

What occurs when work is done against frictional forces?

• a rise in the temperature of the object occurs

• Kinetic energy is converted to heat

Why does air resistance slow down a projectile?

The object does work against the air resistance

Kinetic energy is converted into heat slowing down the object