Question

At what distance from a convex mirror having focall length 5m should an object be placed to that its image has a height equal to 1\3 of the original height ? Also find the distance between object and the image
​

Answer 1

Answer:

0.5 m

Explanation:

His distance from the mirror is the

object distance, treating him as an object, So,

Applying mirror formula

u

1

+

v

1

=

f

1

Also, m(magnification) =

u

−v

m=

⎣

⎢

⎢

⎢

⎡

−(

f

1

)

−

f

2

⎦

⎥

⎥

⎥

⎤

−1

=

2

1

We know,

m=

objectlength

imagelength

Here, object length = Boy's height = 1 m.

So,

m=

1m

imagelength

=

2

1

⇒ image length =

2

1

=0.5m