Question

In figure $p35.26$, parallel rays from the left are focused to a point at two locations on the optical axis. find the position of each location, giving your answer as a distance left or right of the lens.

Short answer

The position of each location, giving your answer as a distance left or right of the lens is$S^{\text{'}}=-1cm$.

Step-by-step solution

Given information 

We need to find the image distance for the mirror .

Simplification 

By using the formula, we have to solve $S^{\text{'}}$

$S^{\text{'}}=\frac{Sf}{S-f}$

Here, $S$is the distance between matter, $f$is the focal length of the mirror and$S\text{'}$is the position of the location.

Substituting the value in equation,

$S^{\text{'}}=\frac{(3cm)+(-1.5cm)}{(3cm)-(-1.5cm)}$

$S^{\text{'}}=\frac{-4.5c{m}^2}{4.5cm}$

$S^{\text{'}}=-1cm.$

Diagrammatic representation