Two Iconic players of Tennis, Roger Federer & Rafael Nadal, with two iconic shots. One with a top spin forehand & other with a slice backhand.
I want to understand the physics of these two shots.
The top spin forehand of Nadal, although looks like it(ball) might go over the baseline when played, lands well inside it & then jumps by an enormously amplified bounce.
The backhand slice of Federer, although looks like it might land mid court, lands just inside the baseline & skids through with an enormously attenuated bounce.
In my knowledge, the two shots behave the way they do because of the relation between velocity of the ball, friction with the air & pressure difference from the top & bottom side.
From basic physics, I know that, as velocity increases, pressure decrease. An example I learned in Physics class: If you stand too close to a fast moving train, you will be sucked in. Because of high velocity of the train, pressure in front decreases while pressure on your back is constant & hence you are moving towards the train.
Applying the same concept, Nadal's top spin forehand makes the ball rotate clockwise. So, Upper half is opposing air, while bottom half is assisting it. More pressure from up, less pressure from down, thus it dives to the ground quickly.
Exactly opposite with Federer's backhand slice. Ball is rotating anticlockwise, Upper half assisting air & lower half opposing it. Less pressure from up, more pressure from down. So its stays afloat longer.
If i am wrong about my Physics up till here, correct me.
My real doubt is, why does the ball, after pitching, bounce more (for Nadal) & less (for Federer) Can anyone explain this physics. Assume they are playing on Clay court
Here is a link to Roger Federer's best backhand slices In the video, first there are a series of flat slices which are retrieved below the knees, much lower than the net. In the next couple of shots, there are some loopy slice which die out after landing.
Here is Nadal's topspin forehand See the 2nd point at 0.20. Look where Federer takes that shot from, near his head.
PS: BTW, Andy Roddick has the best backhand slice in Men's game, but Federer inclusion was for dramatic effect. GOAT nonetheless.