Question

find the focal length of the concave mirror if an object is placed at a distance of 10 cm and image formed at a distance of 10cm

Answer 1

Answer:

concave mirror:

u= -10cm

v= -10cm (image formed is real)

1/u + 1/v= 1/f

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

-1-1/10 = 1/f

-2/10 = 1/f

Therefore, f= 10/-2= -5

f= -5cm