Let's assume the following data was obtained in Atwood's Pulley system. The heavier mass was falling from a height of 0.85 meters and the acceleration of this fall was calculated as 0.175 m/s2. What is the average time of the fall?

Engines for propeller-driven aircraft are limited in their maximum rotational speed by the fact that the tip speed of the propeller must not approach the speed of sound in air (mach i). taking 6 ft as a typical diameter for a propeller of a light airplane and 1100 fils as the speed of sound, find the upper limit on the rpm (revolutions per minute) of the propeller shaft.