The bus is going forward and suddenly stops
Answer:
I don't even know can anybody help this person
They are slowed down.
even air is a medium and will slow down waves (slightly) compared to a vacuum/ space
if the wave hits the medium at an angle it can be 'bent' (refracted) like light through a glass prism
If what your trying to ask is what does it mean its calcium
Answer:
https://youtu.be/stW-C7F7QOg
