Question

An object is placed at a distance of 40cm from a concave mirror of focal length 15cm. If the object is displaced through a distance of 20 cm towards the mirror, By how much distance is the image displaced??.

Answer 1

heyyy here is ur Ans...
Object distance (u)=-20cm

focal length (f)=-15
mirror formula=1/v+1/u=1/f

1/v=1/f-1/u
1/v=1/-15 -1/(-20)
1/v=1/-15 +1/20
1/v=-4+3/60
1/v=-1/60


therefore v=-60....

hope this helps you......