,a light ray travels from glass to water the speed of light in glasss is 2*10^8m/s if the deepeness of water is 400m then how much time will it take Share with your friends Share 0 Neha Gupta answered this $velocityinglass=2\times {10}^{8}m/s\phantom{\rule{0ex}{0ex}}\frac{refractiveindexofwater}{refractiveindexofglass}=\frac{velocityinglass}{velocityinwater}\phantom{\rule{0ex}{0ex}}\frac{1.33}{1.5}=\frac{2\times {10}^{8}}{v}\phantom{\rule{0ex}{0ex}}v=2.25\times {10}^{8}m/s\phantom{\rule{0ex}{0ex}}time=\frac{depth}{v}=\frac{400}{2.25\times {10}^{8}}=177.7\times {10}^{-8}=17.77nanosecond$ 0 View Full Answer