Question

Solve the previous problem if the paperweight is inverted at its place so that the spherical surface touches the paper.

Answer 1

The paperweight is inverted at its place so that the spherical surface touches the paper at 1 cm.          

Explanation:

Given data in the question  :

When the paper weight is rotated to the point where the spherical surface touches the paper

Glass thickness  = 3 cm  

$\mu_{g}=1.5$

$\text { Image shift }=3\left(1-\frac{1}{1.5}\right)$

Treat it as a simple problem of refraction since the upper surface is flat and the Spherical surface touches the object

Image shift  $=3\left(\frac{1.5-1}{1.5}\right)$

                  $=3\left(\frac{0.5}{1.5}\right)$

                  $=3\left(\frac{5}{15}\right)$

                  $=3\left(\frac{1}{3}\right)$

                  = 1 cm        

Therefore, the picture is shown 1 cm above P.