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## Homework Statement

Stacy is throwing a discus. During the throw, she applies an average torque of 90Nm to the discus for 0.3 seconds. The discus has a mass of 1.0kg, and has a radius of gyration of 0.1m about its spin axis. If the initial angular velocity of the discus was zero, what was the angular velocity of the discus at the end of the throw?

## Homework Equations

Wish I learned enough to tell you. Angular acceleration? wf-wi/ delta t. Or angular velocity? Anglef-Anglei/delta t. Or angular momentum? Moment of intertia x angular velocity. Or radius of gyration? Mass x radius of gyration^2

## The Attempt at a Solution

I wrote all of the key numbers, and wrote the equations for all of the above to see where I could plug in the values. I attempted angular acceleration, but I don't have initial angular velocity or acceleration, I tried radius of gyration and got I = 1.0kg x 0.1m^2 = 0.01kgm^2, but I don't know if that's correct or if it should be 0.01, or if o shouldn't have even bothered with that equation. I went to plug it into the angular momentum equation, but realized I have only the initial angular velocity of 0, so Im just lost and don't know what equation I'm even supposed to be using or how simple or complicated it's supposed to be.

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