you are floating at rest in zero gravity. Your mass is 80 kg . You want to propel yourself in one direction by throwing a 10kg ball in the opposite direction . You throw it at 8 m/s. How much work you do? A firehose shoots water at you at a rate of 30 kg/s. The water hits you at 20 m/ sec. Assuming half of the momentum of the water gets reflected back, what's the force of the water on you ? Hello guys! I have no idea how to do these problems :( It dosent seem hard, but I just don't get it! Thank you!