A cargo plane of mass 19,000 kg is flying over level ground at a constant altitude of 4.30 km with a constant velocity of 165 m/s west. Its direction is currently straight toward the top of a mountain. At a particular instant, a house is directly below the plane at ground level. (a) At this instant, what is the magnitude of the plane's angular momentum relative to the house (in kg · m2/s)? kg · m2/s (b) As the plane continues its constant velocity motion, how does the angular momentum vector relative to the house change? Both the magnitude and direction of the angular momentum vector stay the same. The magnitude of the angular momentum vector stays the same, but the direction changes. The direction of the angular momentum vector stays the same, but the magnitude changes. Both the magnitude and direction of the angular momentum vector change. (c) At this same instant, what is the magnitude of the plane's angular momentum relative to the mountaintop (in kg · m2/s)? kg · m2/s