Question

The passengers standing in a stationary bus tend to fall backward, when the bus accelerates suddenly on account

(1) standing carelessly 

(2) inertia of rest 

(3) inertia of motion 

(4) none of these 

Answer 1

Correct option is (2) inertia of rest 

A person sitting in a bus falls backwards if the bus suddenly starts. It is due to the reason that the lower part of his body comes into motion along with the bus where as the upper part of his body tends to remain at rest due to inertia of rest. For the same reason the rider tends to fall back if the horse suddenly starts galloping.