Question

Calculate the focal length of a concave mirror an object distance 20cm image distance 40 cm

Answer 1

Explanation:

1/f=1/u+1/v

u=20cm

v=40cm

1/f=-1/20+1/40

=-1/40

f= -40cm.

Answer 2

Answer:

Explanation:

1/f=1/u+1/v

u=20cm

v=40cm

1/f=-1/20+1/40

=-1/40

f= -40Cm.