A thief is running away in a car with velocity

PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction

Problem

20\,\mathrm{m\,s^{-1}}

. A police jeep is following him. The thief sees the jeep in his rear-view convex mirror of focal length

10\,\mathrm{m}

. He observes that the image of the jeep is moving towards him with velocity

1\,\mathrm{cm\,s^{-1}}

. If the magnification of the mirror for the jeep at that time is

\frac{1}{10}

, find, assuming the police jeep is on the axis of the mirror: (1) The actual speed of the jeep. (2) The rate at which the magnification is changing.