A light ray in air enters and passes through a block of glass , the speed will remain same after it emerges from the block
When a light ray enters into the glass then the speed of the light will get decreased because as a light ray enters into a denser medium , the speed of light get decreased . But when the light ray emerges out from glass , it going from denser to rarer medium , due to which speed will increase and come to same value as it was while entering the glass .
To learn more about denser medium here :
https://brainly.com/question/13613040
#SPJ4
