Question

Figure shows a shperical concave mirror of focal length f=5cm with its pole at (0,0) and principal axis along x-axis. There is a point object at (-40cm, 1cm), find the postion of image.

Answer 1

According to sign converntion,
u=-40cm
`h_(1)=+1cm`
`f=-5cm`
`1/v+1/u=1/(f) rArr 1/v+1/(-40)= 1/(-5),`
`rArr v=(-40)/7 cm`
`(h_(2))/(h_(1))=(-v)/u`
`rArr h_(2)=-(-v)/uxxh_(1)=(-((-40)/(7))xx1)/(-40)=-1/7cm.`
`:.` This postion of image is `((-40)/7cm,-1/7cm)`.