Question

why do we need a medium to make sound travel? Name such mediums and compare their ability to propogate sound.

Answer 1

sound is a mechanical wave and therefore it requires a medium to travel. any medium will propagate sound. but generally the speed of sound in solids is greatest, liquids is a little bit less and in gases it is the least.

Answer 2

we need a medium to make sound travel because sound is a mechanical waves which need a medium to travel
air 340m/s
solid 5000m/s
liquid 125m/s