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

An astronaut is training in an earthbound centrifuge that consists of a small chamber whirled around horizontally at the end of a 4.5 m-long shaft. The astronaut places a notebook on the vertical wall of the chamber and it stays in place.

If the coefficient of static friction is 0.70, what is the minimum rate at which the centrifuge must be revolving?

Express your answer using two significant figures.

w = ________ rad/s

2. Relevant equations

a=v^2/r

F_s= uN

3. The attempt at a solution

u=.7

r=4.5

F_s= uN

f_s=u(mg)

F=ma

F=m(v^2/r)

setting the two forces equal togehter

u(mg)=m(v^2/r)

v= sqrt(ugr)

i got 5.6.

where am i going wrong? thanks

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# Homework Help: Circular Motion, Static Friction

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