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.
Mechanical waves need matter to move. Some examples of electromagnetic waves are Radio, Gamma, X â¦ -rays, Infra-red, and Microwaves Electromagnetic waves are able to travel through a medium of liquids, solids, and geaseous states, or through space where there is no material at all, called vacuum.