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Why is it assumed that angular acceleration is 0 when a ball is midair after rolling off a surface with constant velocity?

Urb
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Deen Qureshi
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  • Rolling w/o slipping? – Gert Jul 30 '20 at 21:30
  • Hello Deen, welcome to Physics StackExchange. I would suggest in the future you try to show some of your own effort to try to solve the problem. This could be useful for other users to give more helpful answers. – Ivan Burbano Jul 30 '20 at 21:45

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Forces acting on each point of the sphere (or any object) due to gravity are the same everywhere when the object is in free fall. Therefore, the net external torque is $0$

Dennis Fr
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  • corrected, thanks – Dennis Fr Jul 30 '20 at 21:40
  • Air drag is going cause a small torque that reduces the rotational speed. Of course it could be other way around where the turbulence on one side may cause the ball to rotationaly accelerate. – JAlex Jul 30 '20 at 21:59