A car is fitted with a convex side-view mirror of focal length 20 cm. A second car 2.8m behind the first car is overtaking the first car at a relative speed of 15 `m/s`. The speed of the image of the second car as seen in the mrror of the first one is:

Options

A. `(1)/(10)(m)/(s)`
B. `(1)/(15)(m)/(s)`
C. `10(m)/(s)`
D. `15(m)/(s)`

Answer

B

Explanation

`(v_i)/(v_O)=-((f)/(u-f))^2=-[(0.2)/(-2.8-(0.2))]^2=-[(1)/(15)]^2`
`(v_i)/(15)=-((1)/(15))^2impliesv_i=-(1)/(15)(m)/(s)`