A place kicker launches a kickoff at an angle of 30 degrees to the horizontal and a velocity of 30 m/s

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is

What can you increase the strength of an electromagnet by

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.