Question

If an object is 20.7 cm in front of a convex mirror that has a focal length of 57.39 cm, how far behind the mirror will the image appear to an observer ?

Answer 1

15.2 cm

Explanation:

Given:

Position of object (u) = -20.7 cm

Focal length of convex mirror (f) = 57.39 cm

We use the following formula to determine the distance behind the mirror:

`\begin{gathered} (1)/(f)=(1)/(v)+(1)/(u) \\ \\ (1)/(57.39)=(1)/(v)+(1)/(-20.7) \\ \\ (1)/(v)=(1)/(57.39)-(1)/(20.7) \\ \\ v=15.2\text{ cm} \end{gathered}`

Therefore the position of the image is 15.2 cm behind the mirror.