When a source of sound moves, the frequency ahead of the source is higher than the frequency behind it.  This change in frequency is called

When both the volume and the absolute temperature of a gas is doubled, the pressure will

The vertical flight of a helicopter is controlled by

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

The emission of energy from the surface of all bodies is

Archimedes’ principle states that

The speed of sound

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?

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

Pascal’s Law states that