# Physics

posted by
**mymi**
.

A 21.0-g metal cylinder is placed on a turntable, with its center 90 cm from the turntable's center. The coefficient of static friction between the cylinder and the turntable's surface is ìs = 0.84. A thin, massless string of length 90 cm connects the center of the turntable to the cylinder, and initially, the string has zero tension in it. Starting from rest, the turntable very slowly attains higher and higher angular velocities, but the turntable and the cylinder can be considered to have uniform circular motion at any instant. Calculate the tension in the string when the angular velocity of the turntable is 70 rpm (rotations per minute).

I converted grams to Kg, cm to m and rpm to radians..etc after that my calculations give me wrong answer, can someone help me.Maybe the coefficient of static friction is not to be used in calculations because metal cylinder and turntable are both in motion........aghhh lost ;(