A block of mass 'm' is attached to a spring. Block is released from rest, when spring is in natural length. Block is along the pricipal axis of concave mirror and size of block is very small. When spring is in natural length then block is at a distance of 20 cm from the mirror, distance (in cm) in which the image formed by mirror oscillates is (mass of the block `=5xx10^(-2)` kg, spring constant k=20 N//m)

Answer

`0010`

Explanation

`(2mg)/k=5xx10^(-2)`
`1/v=1/f-1/u`
`1/v=1/(-10)-1/(-20)=(-2+1)/20`
`v=-20` cm
`d_(1)=20` cm (initial distance of image from mirror)
`1/v=1/(-10)-1/(-15)=(-3+2)/30`
`v=-30` cm
`d_(2)=30` cm (final distance of image from mirror)
`d_(2)-d_(1)=10` cm(distance in which the image oscillates)