Answer:
image height = 0.1 m
image height if flat mirror 1.5 m
θ = 2.86 degree
θ if flat mirror = 41.10 degree
warning label because image is small than object
Explanation:
given data
focal length = -80 cm = 0.80 m
tall = 1.5 m
cycle distance d1 = 30 m
we from mirror distance = 1.4 m
image of cyclist d2 = 2.2 m
to find out
image height , image height if mirror flat , angular size , angular size if mirror flat and why is there a warning label
solution
we apply here formula
image height / tall = d2 / d1
image height / 1.5 = 2 / 30
image height = 0.1 m
and
image height if mirror flat
so height will be same as object height 1.5 m
and
angular size image formula is
θ = 2tan^-1 ( image height /2d2)
θ = 2tan^-1 ( 0.1 /2(2) )
θ = 2.86 degree
and if mirror is flat
angular size
θ = 2tan^-1 ( image height /2d2)
θ = 2tan^-1 ( 1.5 /2(2) )
θ = 41.10 degree
and
we know image is small than object so we can think object is large distance than in real so if we stop instantly so other person will be surprised he have time to stop vehicle