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Rotational Motion

  • Thread starter nybui
  • Start date
  • #1
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Homework Statement


A solid sphere with mass "m" and radius "r", slides (without rotating) on a frictionless horizontal surface, with speed of V[0].

At time t[0] the sphere roll on a surface with friction "u", at time t[0] the ball is starts rotating as it glides aswell. At time t[1] the ball only rotates.

Homework Equations



What is the balls center mass velocity as a function of time, from time t[0] to time t[1].

The Attempt at a Solution



I have been trying to take a look at the balls inertia and torque on the ball from the friction. But the only result I got was that the ball gains speed, an that is nonsence.

Plzz... help this is a homeasignment that comes down on my final grade.

Homework Statement





Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
Doc Al
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I have been trying to take a look at the balls inertia and torque on the ball from the friction. But the only result I got was that the ball gains speed, an that is nonsence.
You probably have the torque going in the wrong direction. In any case, consider the translational motion.

Hint: What forces act on the sphere? Note that the sphere is slipping. Apply Newton's 2nd law.
 

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