The speed of light changes when it goes from ethyl alcohol (n = 1.361) to carbon tetrachloride (n = 1.461). The ratio of the speed of light in carbon tetrachloride to the speed in ethyl alcohol is

The ratio of the speed of light in carbon tetrachloride to the speed in ethyl alcohol is 0.93

Explanation:

The formula for the refractive index of a medium is given as:

n = c/v

where,

n = refractive index of the medium

c = speed of light in vacuum

v = speed of light in that medium

FOR CARBON TETRACHLORIDE:

n = n₁ = 1.461

v = v₁

Therefore,

1.461 = c/v₁  

v₁ = c/1.461     equation (1)

FOR ETHYL ALCOHOL:

n = n₂ = 1.361

v = v₂

Therefore,

1.361 = c/v₂  

v₂ = c/1.361     equation (2)

Now, dividing equation (1) by equation (2), we get:

v₁/v₂ = (c/1.461) / (c/1.361)

v₁/v₂ = 1.361/1.461

v₁/v₂ = 0.93

Hence, the ratio of the speed of light in carbon tetrachloride to the speed in ethyl alcohol is 0.93

ill do it for 100, also this isnt 80 its 40

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr