A piece of dynamite is used to break apart a huge 30000 kg boulder (approximately 5 m3 sphere) that rolled into a nice suburban middle-class couple's living room about a decade ago in Spring Valley. One 6000 kg piece rolled away at 1.5 m/s N, a 9000 kg piece rolled away at 1.0 m/s S, and an 5000 kg piece rolled away at 3.0 m/s W.
(a) What are the momenta of these three chunks? Remember to express them as 2-D vectors.
(b) In what direction and with what speed did the remaining fourth piece roll away?