Prove that air offers resistance by taking real life examples. from chapter - Matter
format of the report .
material required-
procedure -
observation-
conclusion-​

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

To find speed, or mph, use distance/time.