Question
When the bus or train suddenly starts moving, the passengers tend to fall backward. Explain why.
Solution
When the bus is standing still, the person is at rest. But, when the bus suddenly moves, the upper part of the passenger's body is still at rest due to inertia of rest. The lower part of passenger’s body starts moving along with the bus or train. But, the lower part of the body tends to remain at the same state of rest. Hence, a person falls backwards.
