Children - and teachers - have their own ideas about science, and how the world works.

Pupils may believe that:

• If there is motion, there must be a force acting

• If there is no motion, there must be no force acting

• There cannot be a force without motion

• When an object is moving, there is a force in the direction of its motion • A moving object has a force within it which keeps it going • A moving object stops when its force is used up • Constant speed results from the application of constant force .