A large concave mirror has a radius of curvature of 1.5 m. A person stands 10 m in front of the mirror. Where is the person's image ?

Radius of Curvature (R) = - 1.5 m(concave mirror)

Object distance (u) = -10 m [Object distance is negative in Concave mirror]

Image distance (v) = ?


f = R/2

Focal length (f) = -1.5/2
= - 0.75 m

Mirror Formula


1/v + 1/u = 1/f

1/v = 1/f - 1/u

1/v = 1/(-0.75) - 1/(-10)

1/v = 1/(-0.75) + 1/10

1/v= - 100/75 +1/10

1/v = -4/3+ 1/10

1/v= (-4×10+3)/30

1/v= (-40+3)/30

1/v = -37/30

v= -30/37

v = - 0.81 m

Hence, the person's will be 0.81 m in front of the concave mirror.