Chapter 9, Problem 80P

An object is tracked by a radar station and determined to have a position vector given by $\stackrel{\to }{r}=(3500-160t)\hat{i}+2700\hat{j}+300\hat{k}$, with $\stackrel{\to }{r}$ in meters and t in seconds. The radar station’s x axis points east, its y axis north, and its z axis vertically up. If the object is a 250 kg meteorological missile, what are (a) its linear momentum, (b) its direction of motion, and (c) the net force on it?