When we push or pull an object it is known as force. The force can

·          Change the state of motion.

·          Change the shape of body.

Force is a vector quantity because it has both magnitude and direction.

If a number of forces are applied in the same direction, forces are added. If two forces act in an opposite direction then the net force acting on the body is difference between the two forces.

Forces can be classified as following

Contact forces:

1.       Muscular forces

2.       Frictional forces

Non contact forces:

1.       Magnetic forces

2.       Electrostatic forces

3.       Gravitational forces