A ball of mass $0.37 \,\mathrm{kg}$ is thrown upward along the vertical with a initial speed of $14 \,\mathrm{m\cdot s^{-1}}$, and reaches a maximum height of $8.4 \mathrm{m}$.
- What is the work done by air resistance on the ball?
- Assuming that the air resistance performs roughly the same job during the descent, calculate the speed of the ball when it returns to the starting point.
How do I calculate the work of the air resistance?