How Fast Does the Rim of a Spinning Disk Travel?

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SUMMARY

The discussion centers on calculating the speed of a point on the rim of a spinning disk with a mass of 60.0g and a diameter of 7.00 cm, given a kinetic energy of 0.240 J. The relevant equations include the rotational kinetic energy formula, K = (1/2)I(ω^2), and the moment of inertia for a disk, I = (1/2)M(R^2). The user initially struggled with the calculations but recognized a potential calculation error in their approach.

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Problem 13.30
A thin, 60.0g disk with a diameter of 7.00 cm rotates about an axis through its center with 0.240 J of kinetic energy. What is the speed of a point on the rim?

Homework Equations


m=.06kg
r=.035m
KE=.240J

The Attempt at a Solution



K=(1/2)*I*(w^2)
I=(1/2)*M*R^2

I'm using the formula above but I'm not getting the right answer. My numbers seem way to small. I eventually get w(omega) alone. Where do I go from here. Do i need to solve for the length to figure out rad/s then convert to m/s?

Perhaps I am approaching this wrong.
 
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Calculation error, sorry. Mods you can delete.
 

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