Question

The
focal length ofa
Convex mirror a 30 cm. Ifa
Virtual image is formed a
a distance of 20cm from
the mirror then find the
distance of object.
​

Answer 1

Explanation:

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

1/30=1/20+1/u

1/30-1/20=1/u

2 -3 /60 =1/u ( Lcm)

-1/60= 1/u

u = -60 cm