Question

A lens has a radius of curvature of magnitude R R on its left surface and a radius of curvature of magnitude 2R 2 R on its right surface. Parallel rays entering the lens from the left are focused to a point 145 mm m m to the right of the right surface.

Answer 1

Answer:

$v=-29cm$

Explanation:

From the question we are told that:

Radius $R=2f$

Distance $v=145mm=>14.5cm$

Generally the equation for is mathematically given by

$\frac{1}{f}=\frac{1}{u}+\frac{1}{v}$

Therefore

$\frac{1}{f}=\frac{1}{v}$

$\frac{1}{f}=\frac{1}{14.5}$

$f=14.5cm$

Therefore

$R=2f\\\\R=2*14.5$

$R=29cm$

Generally the equation for Focal Length of the Right surface is mathematically given by

$f_r=\frac{R_r}{2}$

$f_r=\frac{2R}{2}$

$f_r=29cm$

Therefore

$\frac{1}{29}-\frac{1}{14.5}=\frac{1}{v}$

$\frac{1}{v}=-\frac{1}{29}cm$

$v=-29cm$