A convex mirror with a radius of curvature of 3 m is used as rear view mirror for a vehicle. If a bus is located at 5m from this mirror, find the position, nature and size of the image.
Given, R = 3 m (For convex mirror)
f = 3/2 = 1.5 m ; u = -5m;v =?
The mirror formula is 1/f = 1/u + 1/v
1/1.5 = 1/-5 + 1/v
1/v = 1/1.5 + 1/5 = 5+1.5/7.5 = 6.5/7.5
v = 7.5/6.5 = 1.15 m
The image is virtual seen at the back in the mirror.
Magnification, m = -v/u = -1.15 /-5 = 0.23
image is erect and smaller in size by a factor of 0.23.