Question

find. magnifacation height of object when a cincave mirror forms an image of size 5cm of focal length 4cm.the image distance in the given case is 9cm​

Answer 1

Answer: force between two charged point is F. if we extend the distance between them twice

Explanation:

Answer 2

Answer:

$3.2cm$

Explanation:

Given:-

Size $(h)=5cm$

Focal Length $(f)=-4cm$

Image Distance $(v)=9cm$

To find:-

Magnification $(m)$

Solution:-

$\frac{1}{f}=\frac{1}{v}+\frac{1}{u}$

$\frac{1}{-4}=\frac{1}{9}+\frac{1}{u}$

$-\frac{1}{4}-\frac{1}{9}=\frac{1}{u}$

$\frac{-9-4}{36}=\frac{1}{u}$

$\frac{-13}{36}=\frac{1}{u}$

$u=\frac{-36}{13}$

$u=-2.8cm$ (approx)

$m=\frac{-v}{u}$

$m=\frac{-9}{-2.8}$

$m=\frac{9}{2.8}$

$m=\frac{90}{28}$

$m=3.2cm$ (approx)

∴ Magnification height of the object = $3.2cm$