What is mechanical waves?
A mechanical wave is a type of wave that needs a medium for it to travel. The waves are known to only convey energy and cause local vacillation of material. For a material to cause a mechanical wave, it has to have a primary energy input. Check out http://www.tutorvista.com/content/physics/physics-i/wave-motion-sound/mechanical-and-electromagnetic-waves.php# for more information.
http://en.wikipedia.org/wiki/Mechanical_waveThey need medium to travel. Have certain energy and do not transfer material.