Question

A man running at a speed $5m/s$ is viewed in the side view mirror of radius of curvature $R=2m$ of a stationary car. Calculate the speed of image when the man is at a distance of $9m$ from the mirror

• A. $0.3m/s$
• B. $0.2m/s$
• C. $0.1m/s$
• D. $0.05m/s$

Answer 1

Answer: (C)

$d=+\ln$
$u=+9m$
By mirror form Jea :-
$\frac{1}{v}-\frac{1}{v}=\frac{1}{7}$
$\frac{1}{v}=\frac{1}{7}+\frac{1}{v}$
$=\frac{1}{1}+\frac{1}{9}$
$V=\frac{9\times 1}{9+1}$
$V=\frac{9}{10}$
After $18sc$
$v=9-5=4.$
$\frac{1}{v}=\frac{1}{v}+\frac{1}{1}$
$v=\frac{u\times 1}{v+1}=\frac{4}{5}$
speed $=0.1m/s$