Answer:
Answer: The distance of the object is -7.5 cm.
Explanation:
Given that,
Focal length f = -10 cm
Height of the image is four times of the object height
Let us considered the height of object is x cm.
So, height of the image h' = 4 x cm
Height of the object h = x cm
Using mirrors formula
\dfrac{1}{f}=\dfrac{1}{v}+\dfrac{1}{u}f1=v1+u1 .....(I)
We know that,
m = \dfrac{h'}{h}=-\dfrac{v}{u}m=hh′=−uv
\dfrac{4x}{x}= -\dfrac{v}{u}x4x=−uv
Now, put the value of u,v and f in equation (I)
\dfrac{1}{-10}=\dfrac{1}{4x}+\dfrac{1}{-x}−101=4x1+−x1
\dfrac{1}{-10}=\dfrac{-3}{4x}−101=4x−3
x = -7.5\ cmx=−7.5 cm
Hence, The distance of the object is -7.5 cm.