Adam and his family pile into the car to drive to Colorado, about 1,648 km away from Naperville. They head west at a rate of 68.4 km/hour and drive for about 12 hours each day. It takes the Giazzon family about two days to travel. What can you calculate with the information provided?

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.