When a force causes an object to move through a distance work is done on the object. So a force does work on an object when the force causes a displacement of the object. • The work done by a force on an object can be calculated using the equation: work done = force × distance moved along the line of action of the force, W = F s. work done, W, in joules, J; force, F, in newtons, N; distance, s, in metres. • One joule of work is done when a force of one newton causes a displacement of one metre. 1 joule = 1 newton-metre. • Students should be able to describe the energy transfer involved when work is done. • Students should be able to convert between newton-metres and joules. • Work done against the frictional forces acting on an object causes a rise in the temperature of the object.