Question

an object is kept in front of a concave of focal length 15cm the image fromed is three time the size of the object calculate the two possible distance of object from the mirror​

Answer 1

Answer:

f= -15cm

m= -3 or+3

case 1

m= -v/u

-3=-v/u

v= 3u----------[1]

1/f=1/v+1/u

1/-15=1/3u+1/u ---------from eqn. [1]

1/-15=4/3u

3u=-60

u=-60/3cm

CASE 2

3=-v/u

v=-3u------[2]

1/f=1/v+1/u

1/-15=-1/3u+1/u

-1/15=2/3u

-3u=30

u=-10

Explanation: