minimario
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Homework Statement
Homework Equations
##v = r \omega ##??
The Attempt at a Solution
The answer is 0...why?
Why is the Instantaneous Speed Zero in this Rotational Motion Problem?
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3 replies · 1K views
##v = r \omega ##??
The answer is 0...why?
Discussion
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Because the "object is rolling without slipping". That means that any point on the objects circumfence that is in contact with the surface on which it is rolling does not move forward of backward on the surface.
(Oh, and saying "the instantaneous speed is 0" is NOT the same as saying "there is no instantaneous speed"!)
(Oh, and saying "the instantaneous speed is 0" is NOT the same as saying "there is no instantaneous speed"!)
spaghetti3451
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The speed of any point of the rolling body is the sum of its speed due to translational motion and its speed due to rotational motion.
What is the translational speed of the point of contact of the rolling body?
What is the rotational speed of the point of contact of the rolling body?
What is the translational speed of the point of contact of the rolling body?
What is the rotational speed of the point of contact of the rolling body?
spaghetti3451
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Well, I now see that there isn't enough data in the problem to calculate the rotational speed of the point of contact. But, the key idea is that the translational speed and the rotational speed are equal and opposite, leading to a net force of zero.