Question

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

• A. Vertically downwards
• B. Along the original parabolic path
• C. Vertically upwards and then vertically downwards
• D. Horizontally followed by parabolic path

Answer 1

Answer: (B)

Along the original parabolic path

Answer 2

The forces leading to the explosion are internal force. They contribute noting to the motions of the centre 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 centre of mass of the fragments of the shell continues along the same of the fragments of the shell continues along the same parabolic as it would have followed. If there were no explosion as shown in figures