Question

A car is fitted with a covex side view mirror of focal length 20cm. A second car 2.8m behind the first car is over taking the first car at relative speed of 15m/s. The speed of the image of the car as seen in the mirror of the first one

Answer 1

Mirror formula:

(1/v) + (1/-280) = 1/20

(1/v) = (1/20) + (1/280)

v = 280/15

v1 = -(v/u)2 vom

v1 = -(280/15X280)2 . 15

v1 = -15/(15x15)

v1 = -1/15 m/s