Forces

What is a force?

It's push or pull.

What can a force do?

It can:

• move an object
• change object's direction.
• stop an object
• change an object's shape.

What is the unit of force?

The unit of force is Newton.

What are the types of forces?

Contact and non-contact forces

What are contact forces?

Those are forces that need touch for example opening a door.

What are non-contact forces?

Those are forces that do not need contact for example magnets.

Give a force.

Friction force.

What is friction?

It is a force between two surfaces.

How does friction depend on the surface?

The rougher the surface the higher the friction.

What is the direction of friction force?

It is opposite to the motion.

What does friction do?

It prevents an object from moving or even stop it.

Give some uses of friction?

For example friction is important to walk.