text: physics question about rotational motion and the law of gravity:? a copper block rests 30.0cm from the center of steel turntable. the coefficent of static friciton between the two is 0.53. the turntable start from rest and rotates with a constant angular acceleration of 0.50rad/s^2. after what time internal will the block start to slip on the turntable? (hint: the normal force in this case equals the weight of the block.) the total acceleration to cause the block to slip is .53g, or 5.194 m/s^2.  the tangential acceleration is alpha*r = .50*.30 = .15 m/s^2 = at the radial acceleration is r*w^2, where w = .5(alpha)t^2, so ar = .30*.5*.50*t^2  ergo, we have   5.194 = root(.15^2 + .005625t^4)  solving for t,  t = 5.506 sec