6. (7 marks) Suppose a migrating bird flies at a constant altitude of 5 km, with a velocity of 42 km/h. At time t = 0 the bird passes directly above a radar station, where t is measured in hours. (a) How fast is the distance between the bird and the radar station changing after 10 minutes? Round your final answer to 2 decimal places and provide units. (b) How fast is the distance between the bird and the radar station changing at time t = 0, i.e. when the bird is directly above the radar station? Is this reasonable? Explain briefly