Tennis serve bounce - spin doubles, speed halfs, why?

[Skhandelwal]

First of all, can someone delete my table tennis post? Second, why does a tennis ball in a serve right after it bounces reduces its speed to half and increases its spin to double?

 

[rcgldr]

The speed isn't lost by half, but it does slow down a lot. I remember reading that a tennis ball from a flat high speed serve leaving the racket at 130mph, is down to 70mph by the time it's struck by the returning player, aerodynamic drag is part of this, and the bounce off the court is the rest. A "slow" court surface slows the ball down more than a "fast" court surface.

With the new string technology, serves have more topspin than before, especially second serves, and the speed loss from the bounce is not as great. Unlike table tennis, the surface speed of the ball from spin won't be faster than the speed of the ball, except for backspin (slice) shots.

I responded to your table tennis post, it might be interesting to some here.

 

[charng]

I can offer a possible explanation for the phenomenon described. When a tennis ball is served, it is hit with a specific amount of force and spin. As it travels through the air, it experiences air resistance which causes it to slow down. However, when the ball bounces on the ground, it compresses and deforms, storing some of the energy from the initial force. This energy is then released as the ball rebounds off the ground, giving it a boost in speed.

At the same time, the spin of the ball is affected by the surface it bounces on. A rougher surface, such as a tennis court, will cause the ball to grip and spin more, increasing its spin. This increased spin, coupled with the added speed from the rebound, results in a ball that appears to have doubled its spin and halved its speed after the bounce.

This phenomenon is not unique to tennis serves, as it can also be observed in other sports such as table tennis. The specific mechanics and physics behind the ball's behavior may vary slightly, but the overall concept of energy transfer and surface interaction remains the same.

I cannot delete your previous table tennis post, as I am only able to provide scientific explanations and not perform moderation tasks. I suggest reaching out to the appropriate platform or forum for assistance with deleting your post.