Question

A boy sitting on top most berth in the compartment of a train which is just going to stop at the railway station, drops an apple aiming at the open hand of his brother situated vertically below his hands at a distance of about 2m. The apple will fall

A. In the hand of his brother
B. Slightly away from the hand of his brother in the direction of the motion of the train
C. Slightly away from the hand of his brother in the direction opposite to the direction of the motion of the train
D. None of these

Answer 1

Hint: In order to find the solution of these kinds of questions we will apply the concept of relative motion. Relative motion is the measure of the motion of an object with respect to the other moving or stationary object. The relative acceleration is defined as the acceleration of an object A which is in the rest frame of another object A.

Complete step by step answer:
Let us assume that the train is moving in the positive x – direction. Since, according to the question the train is about to stop at the railway station which means it is decelerating. So, the acceleration of the train wiltive acceleration be in the negative x – direction.
According to the concept of relative motion,
rela of the apple with respect to the train will be equal to the acceleration of the apple in x-direction, which is equal to zero since the apple is falling in y direction and is subtracted by the acceleration of the train in x-direction which is negative. This results in positive direction.
In other words, according to the question as the train is going to stop at the railway station, the train experiences retardation. Once, the boy throws the apple, it would not experience any retardation in the horizontal direction. Whereas, the boy in the lower compartment experiences the same retardation to
that of the train. Thus, the apple will move in the positive direction, i.e. forward direction.

Hence, option (B) slightly away from the hand of his brother in the direction of the motion of the train is the correct answer.

Note:
Relative velocity is defined as the vector difference between the velocities of the two bodies with respect to each other. All the motions are relative to some frame of reference. For example, if a body is at rest it means that it is not in motion. This means that it is being described with respect to a frame of reference which is moving together with the body.