Question

Figure shows a spherical 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 convention,
`u = -40 cm`
`h_(1) = +1cm`
`f = -5cm`
`(1)/(v) + (1)/(u) = (1)/(f) rArr (1)/(v) + (1)/(-40) = (1)/(-5): v = (-40)/(7) cm, (h_(2))/(h_(1)) = (-v)/(u)`
`rArr h_(2) = - (-v)/(u) xx h_(1) = (-(-(40)/(7))xx1)/(-40) = -(1)/(7)cm. :.` The postion of image is `((-40)/(7)cm, -(1)/(7)cm)`