Apulley system has an efficiency of 74.2%. if you perform 200 j of work, how much useful work does the pulley perform?
a.200 j
b.148 j
c.52 j
d.113 j

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?

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.

When a metal and an bond they do not share electrons