Question

an object is placed at a distance of 15 cm from a concave mirror. images formed at a distance of 10cm in front of the mirror .what is the focal length of the mirror

Answer 1

The focal length of the mirror is 6 cm.

Answer 2

Answer:

We have

v=-10cm

u=-15cm

From mirror formula,

1/f=1/v+1/u

1/f=1/-10+1/-15

1/f=-3-2/30

1/f=-5/30

1/f=-1/6

f=-6cm

Thus the focal length is -6cm(6cm).

Thanks