5. Stella the astronaut is floating in space outside the International Space Station (ISS). She is at rest relative to the ISS, and is holding a 16.5 kg toolbox. The total mass of Stella(including her space suit, etc. but not including the toolbox) is 121 kg. She then throws the toolbox and it moves away from her at 4.22 m s²¹. (a) State your system for the purposes of this problem, and the initial momentum of the system. (b) Show that after throwing the toolbox Stella will move in the opposite direction at 0.575 m s¹.