These questions all probe pupils’ ability to identify the separate forces acting in simple situations, where things are being pushed or pulled.
Q1 begins with a situation where the cause of the forces is obvious. In Qs2-4, ‘invisible’ forces like friction, gravity and reaction of a surface are involved, making these slightly harder.
Qs5-6 are about labelling marked forces; here the emphasis is on being clear about what is exerting the force and what it is acting on. In analysing any example of motion, it is essential to be able to recognise clearly which object each force is acting on, so that you can add up all the forces acting on a given object to predict (or explain) how it moves.
Qs7-10 seem similar to the earlier ones, but have an important difference which makes them
more challenging. These all require the pupil to recognise that all forces come in pairs, so that
if a person pulls an object, he or she also experiences a force exerted by the object, in the
opposite direction.