Understanding Forces and Motion

Why don’t people on the other side of the Earth fall off?

A car is travelling along the road. List three forces acting on it.

What is the unit of force?

A cricketer drops a ball and it speeds up. Are the forces on it balanced or unbalanced?

A boy pushes a toy car along the floor at a steady speed. Are the forces on it balanced or unbalanced?

Mr. Ormon is throwing a ball up in the air and catching it. Copy and complete the sentences using the words ‘balanced’ or ‘unbalanced’. a When Mr. Ormon is holding the ball and it is not moving, the forces on the ball are ... . b When the ball is moving upwards and slowing down, the forces on it are ... . c When the ball is moving downwards and speeding up, the forces on it are ... .

Extension: Mr. Mansur says that if a car is moving, there must be a resultant force acting on it. Mr. Abror says there doesn’t need to be a resultant force acting on it. Who do you agree with, and why?

During a science experiment, Ali and Vali are pushing two books across a table. What force between the two surfaces that are sliding over each other?

Explain how using oil for lubrication reduces friction.

Your father is driving his car on a rainy day. The tyres have treads designed to remove water from between the tyre and the road. Why is it important for your father to have these treads to remove the water?