A 1.2 g pebble is stuck in a tread of a .76 -m-diameter automobile tire, held in place by static friction that can be at most 3.6 N. The car starts from rest and gradually accelerates on a straight rode . How fast is the car moving when the pebble flies out of the tire tread? Alpha= net Torque/moment of Inertia So net torque is 3.6 * .38= 1.368 N-m. Moment of inertia is .5mr^2 so that's .5 * .0012 * .38 ^2= 8.664 * 10^-5. so 1.368 N-m/ (8.664 kg-m^2)= 15789 rad/s^2. Now I need to find Theta and then use wf^2= wi^2 + 2alpha * theta. Then use v=wr. But how do I find theta when I don't know the distance is has traveled around the circle. Is it 2pi*r? I am having trouble because how do I know how Many times this pebble went around the circle? I can't find theta if I don't know the full distance is traveled around the circle since theta= s/r where s is the distance the particle goes on it's circular path. How do I find theta?