A roller-coaster car (Fig. P6.16) has a mass of m = kg when fully loaded with passengers. The path of the coaster from its initial point shown in the figure to point B involves only up-and-down motion (as seen by the riders), with no motion to the left or right.
(a) If the vehicle has a speed of v = m/s at point A, what is the force exerted by the track on the car at this point?
(b) What is the maximum speed the vehicle can have at point B and still remain on the track? Assume the roller-coaster tracks at points A and B are parts of vertical circles of radius r1 = m and r = m, respectively