Free fall in a vacuum: a steel ball and a pith ball with the same diameter are loaded into the top of a large drop tube, which is evacuated to create a very low-pressure environment. The two balls are released simultaneously from the same level to fall to the bottom of the tube. Which one of the following statements is true? a. Steel ball reaches the bottom first. Why?
b. Pith ball reaches the bottom first. Why?
c. Two balls reach the bottom simultaneously. Why?

However, had it been a real sound, the sound's pitch would have been increased by the doppler effect, since the falcon was moving the source of the sound. perpendicular to away from towards at the same speed as

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.

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?