Question

You place an object 30.0 cm from a concave mirror of 15.0 cm focal length. The object is 1.8 cm tall. Find the image position and image height.

Answer 1

Answer:30 cm

Step-by-step explanation:

Given

object distance
`u=30\ cm`

focal length of concave mirror
`f=15\ cm`

height of object
`h_o=1.8\ cm`

Using mirror formula

`\Rightarrow (1)/(v)+(1)/(u)=(1)/(f)`

`\Rightarrow (1)/(v)=(1)/(15)-(1)/(30)`

`\Rightarrow (1)/(v)=(2-1)/(30)`

`\Rightarrow v=30\ cm`

and magnification is

`\Rightarrow m=(-v)/(u)=(h_i)/(h_o)`

`\Rightarrow (-30)/(30)=(h_i)/(1.8)`

`\Rightarrow h_i=-1.8\ cm`

So height of object is same as of object .

Position :image is formed at the spot where object is placed.