Why does earth orbit the sun rather than any other body in the solar system? a) the mutual repulsions among all the planets hold earth in its orbit. b) the earth is closer to the sun than other bodies in the solar system. c) the sun is the most massive object; gravitational attraction is related to mass. eliminate d) the rotational motions of all the planets, including earth, cause them to remain in its orbit around the sun.

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.