Posted by Anonymous on Saturday, October 27, 2012 at 3:13pm.
A coin rests 18.0 cm from the center of a turntable. The coefficient of static friction between the coin and turntable surface is 0.420. The turntable starts from rest at t = 0 and rotates with a constant angular acceleration of 0.650 rad/s2. (a) After 3.00 s, what is the angular velocity of the turntable? b) (b) At what speed will the coin start to slip? c) (c) After what period of time will the coin start to slip on the turntable?

Physics HELP!  Damon, Saturday, October 27, 2012 at 4:58pm
w = alpha t = .65*3 = 1.95 radians/second
friction force = .42 * m * g = 4.12 m
Ac = w^2 R
centripetal force required = m w^2 R
m w^2 R = 4.12 m if slip is outward
Note I am ignoring tangential slip due acceleration, check later
w^2 = 4.12/R = 4.12/.18 = 22.9
w = 4.78 rad/s at spin out
4.78 = alpha t
t = 4.78/.65 = 7.36 seconds
go back and check tangential slip to make sure it is negligible
tangential acceleration = alpha R
= .65 * .18 = .117 meters/s^2
that is tiny compared to g so forget it
Answer This Question
Related Questions
 Physics 1  A coin rests 12.0 cm from the center of a turntable. The coefficient...
 Physics URGENT!!!  A coin rests 18.0 cm from the center of a turntable. The ...
 Physics Elena please help!  A coin rests 18.0 cm from the center of a ...
 Physics Elena please help!  A coin rests 18.0 cm from the center of a ...
 physics  A coin rests 15.0 cm from the center of a turntable. The coefficient ...
 Physics  A coin rests 18.0 cm from the center of a turntable. The coefficient ...
 physics  A coin is placed 33 cm from the center of a horizontal turntable, ...
 physics  A coin is placed 33 cm from the center of a horizontal turntable, ...
 physics  A coin is placed 33 cm from the center of a horizontal turntable, ...
 physics  A coin is placed 33 cm from the center of a horizontal turntable, ...
More Related Questions