Una esfera parte del reposo y desciende durante 8 s por un plano inclinado, con una aceleración de 2,5 m/s2, y después, con la velocidad adquirida, se mueve durante 12 s por el plano horizontal. Calcula: a) la vm durante el movimiento de descenso, b) la vm durante el recorrido horizontal, c) la vm de todo el movimiento.

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.