Question

A stone tied at the end of a string is whirled in a circle. When the string breaks, the stone ___________

(a) Falls down vertically

(b) Flies upwards

(c) Takes a non-uniform path and falls to ground

(d) Flies away tangentially

This question was addressed to me during a job interview.

This intriguing question originated from Friction and Forces topic in section Laws of Motion of Engineering Physics I

Answer 1

Correct option is (d) Flies away tangentially

The best I can explain: The instantaneous velocity of the stone moving round the circle is along the tangent to the circular path. When the string breaks, the centripetal force vanishes. Due to the inertia of motion, the stone flies away tangentially.