* What are mechanical waves? Mechanical waves are disturbances that travel through a medium by transferring energy from one particle to another. They need a physical substance to propagate.

* Examples of media:

* Solids: Sound waves, seismic waves, vibrations in a string

* Liquids: Sound waves in water, ocean waves

* Gases: Sound waves in air

* Why not a vacuum? Mechanical waves cannot travel through a vacuum (like space) because there are no particles to vibrate.

Think of it like this: Imagine a line of dominoes. If you push the first one, it will knock over the next one, and so on. This is similar to how mechanical waves travel. The dominoes represent particles in the medium, and the energy is transferred from one to the next. In a vacuum, there are no dominoes (particles) to transfer the energy.