A thief is running away in a car with velocity of 20 m/s. A police jeep is following him, which is sighted by thief in his rear view mirror, which is a convex mirror of focal length 10 m. He observes that the image of jeep is moving towards him with a velocity of 1 cm/s. If the magnification of mirror for the jeep at that time is 101 . Find
Assume the police's jeep is on the axis of the mirror.
a. the actual speed of jeep,
b. rate at which magnification is changing.