Why are shock absorbers used in motor cycles and cars ?

Explanation

When vehicles are passing over the vertocies and depressions of a rough road they will collides with them for a very short period . This causes impulse effect . Due to large mass and high speed of the vehicles the magnitude of impulse is also high Impulse may cause damage to the car or even to the passengers in it .
The bad effects of impulse is less if time of contact is more . Impulse J = Ft . For the same magnitude of impulse (change in momentum ) if time of contact is high force acting on the vehicle is less . Shock absorbers will absorb the impulse and releases the same force slowly . This is due to large time constant of the springs.
So shock absorbers are used in vehicles to reduce impulse effects .