When an explosive shell travelling in a parabolic path under the effect of gravity explodes in the mid air, the centre of mass of the fragments will move.

Options

A. vertically downwards
B. along the original parabolic path
C. vertically upwards and then vertically downwards
D. horizontallly followed by parabolic path

Answer

B

Explanation

The forces leading to the explosions are internal forces. They contribute nothing to the motion of the center of mass. The total external force, namely the force of gravity acting on the shell is the same before and after the explosion. Therefore, the center of mass of the fragments of the shell continues along the same parabolic-path as it would have followed, if there were no explosion as shown in figure.