An unfortunate astronaut loses his grip during a spacewalk and finds himself floating away from the space station, carrying only a rope and a bag of tools. First he tries to throw a rope to his fellow astronaut, but the rope is too short. In a last ditch effort, the astronaut throws his bag of tools in the direction of his motion, away from the space station. The astronaut has a mass of ma = 113 kg and the bag of tools has a mass of my = 13.0 kg. If the astronaut is moving away from the space station at vi = 2.10 m/s initially, what is the minimum final speed up,f of the bag of tools with respect to the space station that will keep the astronaut from drifting away forever? Ub,f = m/s