Two identical mirrors are placed in a hollow cylindrical tube as show in the figure. A light ray incident on one of the mirrors undergoes multiple reflections. In the length of each mirror is 3 m, and the velocity of light is `3xx10^(8)ms^(-1)`, then find the time raken by the light ray incident on the mirror to come out of the bollow cylinder.

Explanation

` therefore ` from `Delta ABC`
` 1^2 + (1/2)^2 = AC^2`
` AC = (sqrt5)/(2)`
` therefore ` Distance travelled by the light ray,
` d = 6 xx sqrt5 // 2`
` therefore ` Time taken ` = d/v = ( (6sqrt5)/(2))/(3 xx 10^8) = (6 sqrt5 xx 10^(-8))/(6) s`
` therefore ` Time taken by light ray to reach point M is = `sqrt5 xx 10^(-8) s`