Definition of 'perk'. perk (pÉËÊ³k ) Perks are special benefits that are given to people who have a particular job or belong to a particular group. ...a company car, private medical insurance and other perks. One of the perks of being a student is cheap travel.
Sound is a wave, but so are lots of things. More specifically, sound is a wave made of vibrations in the air. When something makes a sound, it vibrates the air molecules, which sends a chain reaction through the air until it reaches our ear drums. When our ears pick up that sound, signals are sent to our brain so that we can interpret what we're hearing.
Space is a very quiet place. But sound doesn't have to move through air-it can just as easily move through water, or through metal wires. In fact, sound moves faster through water than it does through air. But whether in air or in water, sound moves much more slowly than light does.