PSH -A toy car of mass m = 1.68 kg is on a circular track of radius

a) A toy car of mass m = 1.68 kg is on a circular track of radius r = 19.8 cm. The car starts at initial speed vo = 0.24 m/s, and accelerates at a constant rate to final speed vf = 2.56 m/s while making 0.528 complete revolutions around the track Find: 

- , the magnitude of the angular acceleration of the car.
rad/s2 

- t, the time it took to reach the final speed.
s 

b) At the instant the car in question a reaches its final speed, find: 

- f, the magnitude of the frictional force exerted by the track on the car tires to keep the car in a circle.
N 

- a, the magnitude of the total acceleration of the car.
m/s2

c) A disk rotates about a fixed axis through its center of mass and perpendicular to the disk. It starts from rest, and reaches angular speed ω after 5.58 revolutions. Assuming the angular acceleration is constant: how many more revolutions would it take the disk to reach an angular speed of ωf = 3.7ω?