On a given tennis court, the distance between the baseline and
the net is $10$ metres and the distance between the service line
and the net is $5$ metres. The net is $0.9$ metres high. A player
serves the ball directly above the baseline (assume the ball
travels in a straight line).
- What is the minimum height that the ball can be hit at so as to
ensure the ball lands in the service area?
- How far does the ball travel before it hits the ground?
- Assuming the player receiving the serve stays on the baseline
and hits the ball as it crosses the baseline, how should the server
hit the ball so that his opponent has the least time to receive the
serve?
This problem was given by Mikael Brown.