Question

when a bright object is placed 10cm away from concave mirror, it's real image at a distance of 40cm away from the mirror. what is the focal length?​

Answer 1

Answer:

-8cm

Explanation:

formula for focal length is:

1/f=1/u+1/v

1/f=-/10-1/40

1/f=-4-1/40

1/f=-5/40

F=-40/5

F= -8cm

Hope it helps!