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.
Sound waves moving through the air is an example of this type of wave. Transverse waves - movement of the particles are at right angles (perpendicular) to the motion of the energy. Movement of a wave through a solid object like a stretched rope or a trampoline is an example of this type of wave.