Question

A ball is dropped from a spacecraft revolving around the earth at a height of 120 km. What will happen to the ball?

(a) It will fall down to the earth gradually

(b) It will go very far in 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 spacecraft

This question was posed to me by my school principal while I was bunking the class.

Asked question is from Gravitational Potential Field in section Mechanical Properties of Solids of Engineering Physics I

Answer 1

Right choice is (c) It will continue to move with the same speed along the original orbit of spacecraft

To explain: As no external torque is being applied, by the law of conservation of angular momentum, the ball will continue to move with the same angular velocity along the original orbit of the spacecraft.