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 `1/10`. Find
(a) the actual speed of jeep,
(b) rate at which magnification is changing.
Assume the police's jeep is on the axis of the mirror.