Difference between mechanical and electromagnetic waves. explain how you know which type they are.

There are two types of mechanical waves: Transverse and Longitudinal. Transverse waves move perpendicular to the direction of the wave. They have two parts: the crest, which is the highest point; and the trough, which is the lowest point. Longitudinal waves move parallel to the direction of the wave. They have two parts: compressions, areas where particles of the medium are close together; and refractions, areas where those particles are far apart. Mechanical waves need a medium to travel through. Electromagnetic waves can travel through a vacuum. They look like a combination of transverse and longitudinal waves. Examples are UV, Radio, and light. I hope that helps! 

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