How Fast Does the Rim of a Rotating Disk Move?

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SUMMARY

The discussion focuses on calculating the speed of a point on the rim of a rotating disk with a mass of 100.0 g and a diameter of 8.00 cm, which possesses 0.150 J of kinetic energy. The initial attempt to use the linear kinetic energy formula was corrected to emphasize the need for rotational kinetic energy principles. The correct approach involves using the formula for rotational kinetic energy, leading to the determination of angular velocity and subsequently the tangential speed at the rim.

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Homework Statement



A thin, 100.0 g disk with a diameter of 8.00 cm rotates about an axis through its center with 0.150 J of kinetic energy.

What is the speed of a point on the rim?


The Attempt at a Solution



1/2mv^2 = 0.15
v = 1.73m/s

I know
Vt = angular velocity x r

I am not sure how to solve foe the angular velocity
 
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1/2 mv^2 = kinetic energy, correct. However, here you're dealing with rotational KE. You need a different formula. Does that help?
 

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