Question

An object is placed at a distance of 30 cm in front of a concave mirror of focal length 10 cm. Calculate the distance of the image from the mirror.

Answer 1

Answer:

40cm

Explanation:

ANSWER

U=−30

m=

2

1

we know that

m=

U

−V

so V = 15

f=10

for m=

3

1

U

−V

=

3

1

V=

3

−V

f

1

=

V

1

+

U

1

10

1

=

−U

3

+

U

1

U = -40

Therefore for magnification to be

3

1

the object must be placed 40cm upon in front of the mirror.