Question

An object that has a height of 0.4 meter is placed at a distance of 0.7 meter from a concave spherical mirror. An image is formed in front of the mirror and has a height of 0.35 meter. How far from the mirror is the image located? A. 0.2000 m B. 0.6125 m C. 0.8000 m D. 0.4275 m

Answer 1

Answer: B. 0.6125 m

For spherical concave mirror:

Height of the object, $h_o=0.4\hspace{1mm}m$

Height of the image, $h_i=0.35\hspace{1mm}m$

Object distance, u=-0.7 m

we need to find the distance of the image, v.

These are related by the following formula:

$\frac{h_i}{h_o}=-\frac{v}{u}\\ \Rightarrow v=u\times\frac{h_i}{h_o}$

Insert the values:

$v=-(-0.7\times\frac{0.35}{0.4})=0.6125\hspace{1mm}m$

Hence, option B is the correct.

Answer 2

the answer is B. 0.6125 m