a group of persons, as employees, charged with carrying out the work of an establishment or executing some undertaking. a group of assistants to a manager, superintendent, or executive. a member of a staff.
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs. Types of Seismic Waves. There are several different kinds of seismic waves, and they all move in different ways.
A mechanical wave is a disturbance that pulsates through some form of medium: a solid, a liquid, or a gas, carrying the original, initiating energy from one place to another.There are three types of mechanical waves: transverse, longitudinal, and boundary.or a transverse waves, the amplitude is the distance that the wave displaces the medium. The number of waves passing through the medium over time is the waveâs frequency. The higher the frequency of a mechanical wave, the greater the energy it transmits.