Sound waves are compression waves, as seen here. the areas of low pressure within a sound wave, area a for example, are called a) amplitudes. b) frequencies. c) rarefactions. d) troughs.

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

A200-n force is applied to the foot-operated air pump. the return spring s exerts a 2.6-n·m moment on member oba for this position. determine the corresponding compression force c in the cylinder bd. if the diameter of the piston in the cylinder is 40 mm, estimate the air pressure generated for these conditions. state any assumptions. enter a positive number for the compression force c.

On mars a rock falls an unknown vertical distance from a resting position and lands in a crater. if it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? mars' surface gravity is 3.8 m/s2.