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pucr
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Homework Statement
A small coin is placed on a record that is rotating at 33.3 rpm. If the coefficient of static friction between the coin and the record is 0.1, how far from the center of the record can the coin be placed without having it slipped off?
Homework Equations
w = 33.3 rpm = 1.11 rad/sec
Force due to friction = Centripetal force
The Attempt at a Solution
I tried this...
Force due to friction = .1mg = .98m
Centripetal force = ma = m((r*w^2)/r) = mrw^2 = 1.2321mr
soo...
.98m = 1.2321mr
=> .98 = 1.2321r
=> r = .795 m
Unfortunately, the answer should be .08 meters.
I thought at first that I messed up a decimal place somewhere but I can't see where. :-\
I may be going insane...