Question

A boy stands vertically on the floor of a train moving with a uniform velocity on horizontal rails. What is the net force acting on the boy?

Answer 1

The net force on the boy is zero. The weight mg of boy acts vertically downwards. The normal reaction N acts vertically upwards. The two are equal and opposite. Therefore, net vertical force is zero. Since, the train is moving horizontally with a uniform velocity, horizontal acceleration of the boy is also zero. Therefore, there is no horizontal force also on the boy.

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