Question

A ball dropped from a spacecraft revolving around the earth at a height of $300\text{km}$. What will happen to the ball?

• A. It will fall down to the earth gradually
• B. It will go very far in the space
• C. It will continue to move with the same speed along the original orbit of spacecraft
• D. It will move with the same speed, tangentially to the orbit of spacecraft

Answer 1

The correct option is C It will continue to move with the same speed along the original orbit of spacecraft

A ball dropped from a spacecraft revolving around the earth will have zero relative velocity with respect to the aircraft.

But with respect to the centre of the earth its speed will be equal to the speed of the aircraft, i.e. the orbital speed.

Thus, it will continue to move with same speed along the original orbit and force of gravitational of earth will provide it the necessary centripetal force.

Hence, option $\left(c\right)$ is the correct choice.