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What makes a ball curve when thrown?

  1. Oct 22, 2007 #1
    I was golfing the other day, and I was trying to adjust for the hook in my ball. I figured that the area in front of the ball would have a higher concentration of air molecules (more pressure); because of this, I figured that the ball's spin would grab air molecules and bring them in the direction which the front of the ball was moving, creating higher pressure where the air was being taken; because of this, I figured that the ball would go towards the area of lower pressure. However, my intuition seems to have failed.

    Backspin sends the ball upwards, giving it more hangtime. This doesn't work with my theory. Can someone explain to me why I am wrong, and how this actually occurs?
  2. jcsd
  3. Oct 22, 2007 #2


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    Science Advisor

    The spin makes the ball curve as a result of the interaction of the dimples in the ball with the surrounding air. A low pressure area is created due to the increased velocity of flow which is due to the spin. The ball will curve in the direction of the spin.

    There are different theories as to why this happens...Bernoulli's principle is often used...

    Check out this link for more info...(scroll toward the bottom of the page).

  4. Oct 22, 2007 #3


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    Homework Helper

    Take a look at this thread:

    table tennis paradox
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