Question

An object is placed 12cm form a concave mirror which forms its real image at a

distance of 18cm. calculate the focal length of the mirror.​

Answer 1

Answer:

u= -12 cm

v= -18cm

By mirror formula ....

1/F = 1/U + 1/V

1/F = 1/-12 + 1/(-18)

1/F = 1/-12 - 1/18

1/F = -3 - 2÷36

1/F = -5/36

F = -36/5