An air bubble inside a glass slab (µ=1.5) appears 6 cm when viewed from one side and 4 cm when viewed from the opposite side. The thickness of the slab is

Answer

15 cm

Explanation

`(x_(1))/(mu) = 6 therefore x_(1)= 6 xx (3)/(2)` and `(x_(2))/(mu) = 4 , x_(2) = 4 xx (3)/(2)`
`therefore t = x_(1) + x_(2) = 6 + 9 = 15 cm`