# Physics

posted by .

During the semi-finals of the U. S. Open 2007 Grand Slam Tennis, Venus Williams was in the second set of her match against Justine Henin when her serve was clocked (by a radar gun) at 77 miles per hour. The ball left her racquet horizontally at a height of 2.37 m above the surface of the tennis court. Venus was standing at the service line 12.0 m from the net that has a height of 0.9 m. If the ball clears the net and lands within 7.0 m of the net on the other side, the serve is considered “good" according to the regulations of the game because the ball lands inside the service box on the other side of the net. (See the sketch of a tennis court below.) If the ball clears the net but lands beyond the service box on the other side, this serve is considered a fault. The player receiving the service ball cannot hit the ball before it strikes the court inside the service box. (a) With what minimum speed (in SI units) is Venus required to strike the ball for it to just clear the net? State assumption(s) and support your response quantitatively. (b) Was the serve clocked at 77 miles per hour "good" or was it a fault? If this ball goes over the net, how far will it land from the backline of the service box on Justine’s side of the net. Support your response quantitatively. (c) Sketch graphs of the ball’s displacement, velocity, and acceleration as functions of time (six graphs.) (d) Williams’ slowest serve was at 71 miles per hour. She used the same technique described above but she obviously did not strike this ball as hard. After the match, a local sportscaster said "By serving a slower ball that cleared the net, Williams gave Henin more time to react to her serve because the ball was in the air a little longer than when Williams served her fast ball". Does the sportscaster speak with authority on this subject? Use physics principles to support your response.

## Similar Questions

1. ### Math

Fast Freddy was driving his new red Porche down the road at 65 miles per hour when he suddenly saw Officer Friendly behind a bush holding a radar gun. Freddy quickly hit his breaks and slowed his car to 45 miles per hour within about …
2. ### managerial economics

Explain why it would cost Rafael Nadal or Venus Williams more to leave the professional tennis tour and open a tennis shop than it would for the coach of a university tennis team to do.
3. ### English

Is the following a compound complex sentence?
4. ### physics

7. An airplane has a gun that fires bullets straight ahead at the speed of 600 miles per hour when tested on the ground while the plane is stationary. The plane takes off and flies east at 600 miles per hour. Explain whether each of …
5. ### Pre-Calculus

Venus orbits the sun in an approximately circular path. Venus is about 67 million miles from the sun. A comet is located 80 million miles north and 73 million miles west of the sun. The comet follows a straight-line path and exits …
6. ### Math

venus and fumiko are coworkers at a rental store Venus earns 2.25 per hour than Fumiko together they earn 14.55 per hour how much money per hour does Venus earn
7. ### math

In a grand prix automobile race, Speedy Ryder averaged 110 miles per hour for the first half of the course and 130 miles per hour for the second half of the course. Cannonball Carter maintained a constant speed of 120 miles per hour …
8. ### Trigonometry- Help!

After one hour in flight, an airplane is located 200 miles north and 300 miles west of the airport. What is the magnitude of the plane's velocity?