Mechanical waves require a medium to travel through. Examples of mechanical waves are sound waves, water waves, a vibrating string. (See related link). Electromagnetic waves â¦(such as light, radio waves, X-rays, microwaves) do not need a medium to travel through, so these are not mechanical waves.
Photostat definition, a camera for making facsimile copies of documents, drawings, etc., in the form of paper negatives on which the positions of lines, objects, etc., in the originals are maintained. a copy made with this camera.
The definition of compile means to gather a number of things together into one. Collecting photos for a photo album is an example of to compile. -Â·piledâ², -Â·pilâ²ing. 1  to gather and put together (statistics, facts, etc.) in an orderly form.