# Describe the image of an object that is 38cm from a concave mirror that has a focal length of 10cm.

## Question:

Describe the image of an object that is 38cm from a concave mirror that has a focal length of 10cm.

## Mirror Formula:

The mirror formula gives the relation between object distance(u), image distance(v) and focal length (f).

The mirror formula is:

{eq}\displaystyle \frac{1}{f} = \frac{1}{v} + \frac{1}{u} {/eq}

Concave mirror is also called converging mirror.

To find image distance or position of image

Given

Object distance (u) = -38 cm

Focal length (f) = -10 cm

Find image distance (v)

Using Mirror formula and substituting value of v , f in formula

{eq}\begin{align} \frac{1}{f} &= \frac{1}{v} + \frac{1}{u} \\ \frac{1}{v} &= \frac{1}{f} - \frac{1}{u} \\ \frac{1}{v} &= \frac{1}{-10} - \frac{1}{-38} \\ \frac{1}{v} &= -\frac{1}{10} + \frac{1}{38} \\ \frac{1}{v} &= -\frac{28}{10\times 38} \\ \frac{1}{v} &= 0.07368 \\ v &= -13.57 \ cm \end{align} {/eq}

Negative sign shows that image is formed in front of concave mirror.