Antares is the bright blue star representing the left shoulder of the constellation Xerxes. All the following statements about Antares are true. Which one can you infer from its blue color? It is much more massive than the Sun.
It is moving away from us.
Its surface is hotter than the surface of the Sun.
It is much brighter than 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.