2.A hollow vertical cylinder with radius R spins about its vertical axis of symmetry. A stone is held to the inner cylinder wall by static friction. Express the maximal period of rotation in terms of the radius and the coefficient of static friction.

3.A 1050 kg car travels around a turn of radius 70 m on a flat road. If the coefficient of friction between tires and road is 0.80 what is the maximum speed the car can travel without slipping? Is this result dependent on the mass of the car?