A convex mirror is on the exterior of the passenger side of many trucks (see the
ID: 1444749 • Letter: A
Question
A convex mirror is on the exterior of the passenger side of many trucks (see the figure(Figure 1) ). If the focal length of such a mirror is -40.0 cm,
Part A) What will be the location of the image of a car that is 1.5 m high and 110 m behind the truck mirror?
Part B) What will be the height of the image of a car that is 1.5 m high and 110 m behind the truck mirror?
Part C) What will be the location of the image of a car that is 1.5 m high and 11.5 m behind the truck mirror?
Part D) What will be the height of the image of a car that is 1.5 m high and 11.5 m behind the truck mirror?
Explanation / Answer
f = -40 cm , do = 110 m, ho =1.5 m
part A: From mirror formula
(1/f) = (1/u) + (1/v)
-(1/40) = -(1/110) +(1/v)
v = -62.86 cm
image position is 62.86 cm from the mirror
Part B: from lateral magnification
hi/ho = -di/do
hi/1.5 = (62.86/110)
image height hi = 0.857 m
Part C:
f = -40 cm , do = -11.5 m, ho =1.5 m
From mirror formula
(1/f) = (1/u) + (1/v)
-(1/40) = -(1/11.5) +(1/v)
v = 16.14 cm
image position is 16.14 cm from the mirror
Part D: from lateral magnification
hi/ho = -di/do
hi/1.5 = (16.14/11.5)
image height hi = - 2.1 m