Physics (AS & A Level) · May / June 2020 · Paper 11 · Question 9

The resultant force $F$ on a raindrop of mass $m$ falling with velocity $v$ is given by the equation $F = mg - kv^2$ where $k$ is a constant and $g$ is the acceleration of free fall. What is the velocity of the raindrop when it reaches a constant (terminal) velocity?

1. A$\sqrt{\dfrac{k}{mg}}$
2. B$\dfrac{k}{mg}$
3. C$\sqrt{\dfrac{mg}{k}}$
4. D$\dfrac{mg}{k}$

As printed in the paper