A bicycle and its rider have a total mass of 74.0 kg. Each of its wheels can be modeled as a thin hoop with mass 1.30 kg and diameter of 70.0 cm. When the brakes are applied, two brake pads squeeze the rims of each wheel. Assume that the four brake pads exert normal forces on the wheels that are equal and constant in magnitude. The coefficient of kinetic friction between a brake pad and a wheel is 0.90. The bicycle is moving on level ground with a linear speed of 7.5 m/s. When the brakes are applied, the bicycle is stopped in 4.5 s. Find the magnitudes of 

(a) The static frictional force exerted by the road on each tire; 

(b) The angular acceleration of the wheels; 

(c) The magnitude of the net torque on each wheel; and 

(d) The normal force applied to a wheel by each of the brake pads.