Posted by **Jordan** on Sunday, October 24, 2010 at 12:16pm.

An electric drill starts from rest and rotates with a constant angular acceleration. After the drill has rotated through a certain angle, the magnitude of the centripetal acceleration of a point on the drill is twice the magnitude of the tangential acceleration. What is the angle?

- physics -
**drwls**, Sunday, October 24, 2010 at 12:38pm
w = a*t where a is the angular acceleration, in rad/s^2, and t is the time since it started to accelerate

R w^2 = R*(a*t)^2 = 2 R*a

R cancels out. a^2* t^2 = 2a

t = sqrt (2/a)

I cannot provide a numerical value without knowing the acceleration rate.

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