The minimum deviation produced by a glass prism of angle 60° is 30°. If the velocity of light in vaccum is $3 \times 10^8 m/s$. Then what is the velocity of light in glass in m/s ?
$ n = { sin \left( {A + \delta m \over 2 } \right) \over sin {A \over 2 } }$ $ velocity of light in glass = C_{air } \over n $