Rotorcraft. A rotorcraft uses lift created by rotor blades.

Nikola Tesla. Tesla was an inventor, mechanical engineer and electrical engineer.

England. A CAT scan is a series of x-rays that are assembled by a computer to create detailed images.

P. Sometimes animals can actually hear the P waves of an earthquake before the waves are felt.

1566. Kilojoule is the preferred measure of energy preferred by the international community.

Moon. The moon is about 1/80th the size of the Earth in mass.