a) Take a pencil. Just push its rounded end on your palm.

Question

Change in effect of force with area of contact:

a) Take a pencil. Just push its rounded end on your palm. Now push from the other side of the pencil gently so that the sharp end is on your palm. What difference did you experience? Why?

b) Why do the porters place turbans (talapaga) on their head when they have to carry heavy loads?

c) Why do school bags and shopping bags have broad straps as handles?

d) Have you ever wondered why the lorries carrying loads have a large number of broader tyres?

Answer 1

a) It applies more force when sharp end touches the palm.

b) The reason is, they are increasing surface area there by they are decreasing the force applied by object.

c) As the surface area increases the force applied by object decreases.

d) The effect of force depends on the area of contact on which the force is acting. When the area of contact is more then the force acting is less. So lorries have a large number of broader tyres to carry heavy loads.