A stone is dropped from rest from the top of a 100 m high cliff. (Assume acceleration due to gravity $g=10$ m/s²). Calculate the velocity of the stone after 3 s and the distance it has fallen in those 3 s.

Step-by-step solution

1. Velocity: use $v=u+gt$ with $u=0$.
2. $v=0+10\times 3=30$ m/s.
3. Distance: use $s=ut+\frac{1}{2}g{t}^2$ with $u=0$ and $t=3$ s.
4. $s=\frac{1}{2}\times 10\times 9=45$ m.

Concept tested: Kinematic equations for free fall

Published 10 October 2026 · How this solution was prepared and checked