Chapter Review:

• A push or a pull on an object is called a force.

• A force arises due to the interaction between two objects.

• Force has magnitude as well as direction.

• The force resulting due to the action of muscles is known as the muscular force.

• Muscular force can be applied only when it is in contact with an object, it is also called a contact force.
• The force acts opposite to the direction of motion and this is responsible for changing the state of motion of objects. It arises due to contact between the surfaces is called frictional force.
• The force which is felt by the objects without any contact is known as non-contact force. 
• The force exerted by a charged body on another charged or uncharged body is known as electrostatic force.
• Every object attracts each other and pulls toward itself. Such force which applied on objects is known as Gravitational force and gravitation.
• The force acting on a unit area of a surface is called pressure.                                Pressure = force / area on which it acts 

• The pressure exerted by this air is known as atmospheric pressure.

• Liquids and gases exert pressure on the walls of their containers.