A64-kg astronaut is in space, far from any objects that would exert a significant gravitational force on him. He would like to move toward his spaceship, but his jet pack is not functioning. He throws a720-g socket wrench with a velocity of5m/s in a direction away from the ship. After 0.50 s, he throws an800g spanner in the same direction with a speed of8m/s. After another 9.90 s, he throws a mallet with a speed of6m/s in the same direction. The mallet has a mass of1140g. How fast is the astronaut moving after he throws the mallet?
m/s