I understand the basic formula per say of the apparent shift due to glass slab (t(1-1/u)) But when a question comes on i just don't know how to proceed. For ex this question came on my test and i just couldn't visualise how to make ray diagram or even attempt it.
'"There is a dust particle on a a glass slab of thickness t and refractive index 3/2 . When seen from one side if the slab, the dust particle appears at a distance 6 cm. From the other side it appears at 4cm. Find the thickness t of the glass slab"
The Attempt at a Solution