Question

A woman stands 1.8 meters from a convex mirror with focal length -0.7 meters. If she is 1.6 meters tall, calculate the height of her reflection. (Give your answer in meters)

Answer 1

We have given that,

A woman distance (u) = - 1.8 meters

focal length = -0.7 meters

Height of object = 1.6 meters ,

To find height of image of women (hi) = ?

Now we have the mirror formula as,

1/v +1/u =1/f

So that on plugging values we will have

1/v = 1/-0.7 - 1/1.8

So that v = - 0.504 m

Now form the magnification formula of the mirror we have,

M = - v/u = hi/ho  

So that, hi = - v/u × ho = 0.504×1.6/1.8 = 0.448 m

Hence height of her reflection is = 0.448 m