A 68.5-kg astronaut is doing a repair in space on the orbiting space station. She throws a 2.25-kg tool away from her at 3.20 m/s relative to the space station. With what speed and in what direction will she begin to move?

Solution 18E Step 1 of 1: Here astronaut and tool is a system. Consider the direction of the tool is +x direction. Initially both astronaut and tool at rest ,so vA 1x= v t 1x 0 vT 2x= 3.2 m/s m A 68.5 kg m = 2.25 kg T v = A 2x Conservation of momentum of the system is p1x p 2x 0 = p2x 0 = m v + m v A A 2x T T 2x v = mT T 2x A 2x m A 2.25 kg×3.2 m/s = 68.5 kg = 0.105 m/s Astronaut speed is 0.105 m/s and the direction is opposite in which she throws the tool.