A basketball is thrown for a free throw at 10m/s an angle of 20 degrees, makes it into the hoop and lands on the ground. Find the initial velocity in the y direction. ​

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.