A stone with mass $m$ drops from rest from the top of a cliff of height $h$ into the sea beneath. Immediately before reaching the sea, the stone has speed $v$. What is the average force of air resistance acting on the stone while it falls?
- A$mg$
- B$\dfrac{m(v^2 - 2gh)}{h}$
- C$m\left(g - \dfrac{v^2}{2h}\right)$
- D$m\left(gh - \dfrac{v^2}{2}\right)$