A train is travelling on a curved track. At a point where the train is travelling at a speed of 132ft/s and the radius of curvature of the track is 3000 ft, the engineer hits the brakes to make the train slow down at a constant rate of 7.5 ft/s^2.
a) Find the magnitude of the acceleration vector at the instant the engineer hits the brakes.
b) Approximate the angle between the acceleration vector and the unit tangent vector T at the instant the engineer hits the brakes.
Any help would be appreciated.