A crate of mass 100 kg is being pushed in a straight line across a horizontal floor at a constant speed of 4.0 m/s.
The coefficient of kinetic friction between the crate and
the floor is 0.3. Find the net force on the crate.

The two required components for a generator

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

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.