Question

IF THE FOCAL LENGTH IS 15CM AND IMAGE DISTANCE IS 20CM THEN FIND THE OBJECT DISTANCE? ​

Answer 1

answer: v=-60

Explanation:

1/v=1/f- 1/u

1/-15-1/-20= -4-(-3)/6

=-1/60

v=-60

image is real and inverted

Answer 2

Explanation:

in case of concave mirror, 1/f=1/v +1/u. Now put 1/-15-1/-20=1/u.-4+3/60(60is lcm of 15 and 20)Then1/u=-1/60. Then u =-60