engineering science
posted by lindiwe .
The spherical side mirror on a car is convex and has a radius of curvature of 25 cm. Another car is following, 20 m behind the mirror. If the height of the car is 1.6 m, how tall is its image?

1/do+1/di=1/f is the equation, solve for di.
then, having di (remember the sign conventions for convex mirrors),
M=di/do=hi/ho 
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f=R/2; f=25/2; f=12.5
1/do+1/di=1/f
1/2000+1/di=1/12.5
.0005+1/di=.08
1/di=0.0805
di=12.42cm
1.6*di/do=1.6*2000/12.42=0.0099=1 cm