Amass m is placed on the inside surface of a vertical cylinder that is rotating about its central axis. if the radius of the cylinder is 0.5 m and the angular velocity of the cylinder is 6 rad/s, what minimum value of µs (the coefficient of static friction) is required to keep the mass from slipping down the wall of the cylinder?

Explanation:

In order for the friction to be sufficient to keep the mass from falling, the force of gravity (mg) must be the same friction force() and  the centripetal force () must to have the same value of the normal force (N):

Recall that , so we have:

Recall that . The centripetal acceleration is given by:

Finally, replacing :

answer; /// the above statement is (true);

d. platinum would have the greatest temperature increase because it has the lowest specific heat.