(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A high-speed drill rotating ccw at 2200rpm comes to a halt in 2.80 s. What is the drill's angular acceleration?

2. Relevant equations

(where w = angular velocity)

w = 2╥/T

v = wr

a = v^2/r

a = w^2*r

3. The attempt at a solution

I start by calculating w. So first I took it to rev per second and then second per revolution which came to be 0.027 seconds per revolution. So w = 2╥/0.027 = 232.71 radians. Now I'm stuck because I don't have r (radius). I've tried going backwards to get r from v, but to no success since v depends in r as r depends in v. Every equation relating to acceleration seems to need r but I don't see how I can get it. Any ideas would be appreciated. Thanks.

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# Homework Help: What is the drill's angular acceleration?

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