An alligator crawls 25\,\text m25m25, start text, m, end text to the left with an average velocity of -1.2\,\dfrac{\text m}{\text s}−1.2 s
m

minus, 1, point, 2, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction.

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.