The speed of sound

Archimedes’ principle states that

The emission of energy from the surface of all bodies is

The transfer of heat by the movement of a heated fluid is

The vertical flight of a helicopter is controlled by

If the pressure of a dry gas is reduced by one third, the volume will

A weight of sixty pounds is supported by pulleys which are supported by four ropes.  How much force must be applied to move the weight?

In a hovering helicopter equipped with a tail rotor, directional control is maintained by

Pascal’s Law states that

The elevators of a conventional airplane are used to provide rotation about the