Question

A convex mirror has a focal length of 15cm. If the object is 35cm from the mirror and is 2cm tall, what is the magnification? Round your answer to one decimal place.

Answer 1

Answer:

The magnification is 0.3

Explanation:

Given:

The focal length of the convex mirror, f = 15 cm

for convex mirror f = -f = -15 cm

The distance of object, u = 35 cm

Height of the object, h = 2 cm

Now, using the mirror formula, we have

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

where, v is the distance of the image

on substituting the values, we get

$\frac{1}{-15}=\frac{1}{35}+\frac{1}{v}$

or

$-\frac{1}{v}=\frac{1}{35}-\frac{1}{-15}$

or

v = -10.5 cm

now, the magnification (m) is given as:

m = $-\frac{v}{u}$

on substituting the values, we get

m = $-\frac{-10.5}{35}$

or

m = 0.3

Hence, the magnification is 0.3