This girl is using a ...... forces to pull on the empty sledge

The things below that you can push, except.....

A piece of equipment that measures the size of a force is

The unit of force is ....

A ball is lying on the floor. When will the ball move?

The volcano explodes is one example of ...... force

When you rub together your hands, you will feel warm, because

You need to be careful when you walk in ice surface, or you'll fall down. It is because the smooth surface will give ....... friction.

The fire comes up from the wood, because there is ........... between wood and stick.

Which is object needs the largest force to make it move?

Which the activity need the smallest force to do?

We can ....... the ball to make it moves.

The statement below about forces can change the shape of things is......

Which surface creates the biggest friction with a skateboard?

This street in the picture has ........ friction

The wind creates a forces on the sail to make the boat ...... through the sea.