Chapter 14, Problem 34P

The 150-lb car of an amusement partk ride is connected to a rotating telescopic boom. When r = 15 ft, the car is moving on a horizontal circular path with a speed of 30 ft/s. If the boom is shortened at a rate of 3 ft/s, determine the speed of the car when r = 10 ft. Also, find the work done by the axial for F along the boom. Neglect the size of the car and the mass of the boom.

The 5-lb collar slides on the smooth rod, so that when it is at 4 it has a speed of 10 ft/s. If the spring to which it is attached has an unstretched length of 3 ft. and a stiffness of k = 10 lb/ft, determine the normal force on the collar and the acceleration of the collar at this instant. Solution: 2 ft 10 ft/s

The roller coaster and its passenger have a total mass m. Determine the smallest velocity it must have when it enters the loop at A so that it can complete the loop and not leave the track. Also, determine the normal force the tracks exert on the car when it comes around to the bottom at C. The radius of curvature of the tracks at B is p3 , and at C it is Pc. Neglect the size of the car. Points A and C are at the same elevation. B PB