Explain giving two examples each of :

1. Contact forces, and
2. Non-contact forces.

Classify the following amongst contact and non-contact forces :

1. frictional force,
2. normal reaction force,
3. force of tension in a string.
4. gravitational force,
5. electrostatic force,
6. magnetic force.

Give one example in each case where :

1. the force is of contact, and
2. force is at a distance.

A ball is hanging by a sting from the ceiling of the roof. Draw a neat labelled diagram showing the forces acting on the ball and the string.

A spring is compressed against a rigid wall. Draw a neat and labelled diagram showing the forces acting on the spring.