Final answer:
The given scenario involves calculating the trajectory of a tennis serve using principles of projectile motion; however, the original question about what is not a service fault seems to be unrelated to the detailed scenario. Bouncing the ball before serving is not a service fault, while stepping over the line, serving out of bounds, and serving into the net are all faults.
Step-by-step explanation:
The question asks about the angle at which a tennis player should serve the ball so that it just crosses over the net. Given that the tennis player is serving at a speed of 170 km/h, from a height of 2.5 m, from the baseline that is 11.9 m away from the net, with the net height being 0.91 m, we are to determine the angle for the serve and whether the ball will land in the service box. The service box is 6.40 m from the net.
In order to solve this problem, we would use the principles of projectile motion. We need to calculate the trajectory of the ball considering the speed of the serve (converted to meters per second), the height at which the ball is hit, and the distances involved. The angle required for the ball to just cross the net can be calculated using kinematic equations, but without specific values for the angle, we cannot definitively answer whether the serve would be inbounds without performing the actual calculations.
However, since the student's question is related to what constitutes a service fault in a game rather than the physics of the serve, the given information seems to be a mix-up with a different question. To clarify the original question: which of the following is not a service fault? If a server bounces the ball before serving, it is not a fault. Stepping over the line (service fault), serving out of bounds (fault), and serving into the net (fault) are all considered service faults.