Pushes, pulls and how things move
Physics · Key Stage 1 · The School
Two kinds of force
A PUSH moves something away from you; a PULL brings it towards you. Opening a door, kicking a ball, and pressing a button are pushes. Opening a drawer, tugging a rope and picking something up are pulls. Almost every movement you can name starts with one or the other.
What a force can do
A push or a pull can make something START moving, STOP moving, go FASTER, go SLOWER, CHANGE DIRECTION, or CHANGE SHAPE. Squashing a sponge changes its shape without moving it anywhere. Hitting a ball back changes its direction. Naming which one is happening is the useful skill.
Why things stop
A rolling ball does not keep rolling for ever, because rubbing against the ground slows it. That rubbing is called FRICTION. There is more friction on carpet than on smooth wood, which is why a ball rolls further on wood. Friction is also useful — it is what stops your shoes slipping.
Give a ball exactly the same push along three surfaces: a smooth wooden floor, a short carpet, and a thick towel. Mark where it stops each time. Wood furthest, carpet less, towel least. The push was identical every time, so the push cannot be what changed. What changed is how much the surface rubbed against the ball — friction — and you have just measured it three times.