Question

An object is placed near a concave mirror having a radius of curvature of magnitude 60 cm. How far should you place the object from the mirror so that the lateral magnification produced by the mirror will be 2.5?

Answer 1

u = 18 cm

Step-by-step explanation:

given,

radius of curvature = 60 cm

magnification of mirror = 2.5

distance of object = ?

R = 2 f

f = R/2

f = 60/2 = 30 cm

`m = -(v)/(u)`

`2.5 = -(v)/(u)`

v = -2.5 u

now,

Using mirror formula

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

`(1)/(30) = (1)/(-2.5u) + (1)/(u)`

`(1)/(30) = (0.6)/(u)`

u = 0.6 x 30

u = 18 cm

distance of object be equal to u = 18 cm