Posted by Emily Gutenber on .
a 70 kg object sits without sliding on a horizontal platform that rotates at a constant rate of one revolution every 6 seconds about a fixed vertical axis. The object moves on a circle of radius r=2m. If meu is now .4 what is the max distance from the cetner that the object can occupy to rotate with out sliding?
Ap Physics -
You don't need to know the mass or initial radius to answer your questio.
The angular velocity remains
w = 2 pi rad/6 s = 1.047 rad/s
I assume that waht you call meu is the coefficient of STATIC friction, which is what matters here. I will call it mu.
The maximum no-slip radius R when rotating at angular velocity w is given by the relation:
Max. no-slip friction force = centripetal force
M*g*mu = M*R*w^2
The mass M cancels out.
R = g*mu/w^2 = 3.58 m