Astationary motion detector sends out a sound wave of frequency f = 3.3-hz towards an approaching car. the wave is reflected off the car and the reflected wave is picked up by the motion detector. when the reflected wave is superimposed on the original wave, it is found that the sum produces a beat frequency fbeat = 0.070-hz. find the speed of the car. you may assume the speed of sound in air to be 340-ms-1

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

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.

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?