The primary responsibilities of human resources are: 1  C - Compensation. 2  H - Human resource development. 3  E - Employee and labor relations. 4  S - Safety and health. 5  S - Staff.
A new technique uses sound waves to levitate objects and move them in mid-air. Credit: Dimos Poulikakos View full size image. View full size image. Hold on to your wand, Harry Potter: Science has outdone even your best Leviosa! levitation spell.
Waves are moving energy. Light energy moving from the computer screen to your eye moves as light waves. Sound energy moving from a radio to your ear moves as sound waves. Waves can move along ropes, strings or across the surface of water.n transverse waves the particles vibrate at right angles to the movement of energy. Examples are light waves, water waves and all electromagnetic waves. In longitudinal waves the particles vibrate in the same direction as the movement of energy. Examples are sound waves and seismic waves.