Spinning ball and its trajectory

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In table tennis, topspin causes the ball to drop faster than a non-spinning ball due to the effects of air pressure and friction. The Bernoulli principle explains that faster airflow beneath the ball reduces pressure, while turbulence on top increases it, contributing to the ball's downward trajectory. Friction plays a crucial role, as it enhances the ball's spin and affects airflow around it. The discussion also touches on the similarities between topspin in table tennis and curveballs in baseball, emphasizing the importance of rotational motion and air dynamics. Understanding these principles can help players improve their game by manipulating spin and trajectory effectively.
pixel01
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I play tabletennis and it is obvious that with top spin, the ball go down faster than the one without any spin. I have try to explain by bernoulli, but it seems the result is opposite: top spin ball will drift more!. Anyone can help?
 
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It is the same as a curveball.
Friction is important. That is why pitchers try to scruff up the ball.
The air flow is slowed down on the top side.
The faster flow on the bottom side reduces that pressure by Bernie's theorem.
 
It is the same as a curveball.
Friction is important. That is why pitchers try to scruff up the ball.
The air flow is slowed down on the top side.
The faster flow on the bottom side reduces that pressure by Bernie's theorem.
Also turbulence at the top increases the pressure there.
 
It is probably easier to use the rotational model/Newton's law. The spinning motion combined with the friction directs the air upward behind the ball. Via action-reaction (conservation law), if air goes one way (up), the ball must go the other (down).
 
Meir Achuz said:
It is the same as a curveball.
Friction is important. That is why pitchers try to scruff up the ball.
The air flow is slowed down on the top side.
The faster flow on the bottom side reduces that pressure by Bernie's theorem.
Also turbulence at the top increases the pressure there.

I agree with you that friction is important. But the force caused by friction isn't up or down is it?. Friction just slows down the spin. And turbulence, it is not so clear because sometimes the ball does not fly very fast and with not much of a spin, but the phenomenon is still observed. I don't know at which speed, the turbulence begins to occur in case of a ping pong ball
 
pixel01 said:
I agree with you that friction is important. But the force caused by friction isn't up or down is it?.
Since the ball is rotating in the direction of motion, the friction force on the top surface is much larger than on the bottom surface. But even without that effect, the friction causes the air to rotate around the ball.
 

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