- #1
Slinkie
- 6
- 0
A man in space fires a CO2 pellet rifle, the pellet accelerates to 500 fps. The KE is calculated to be 4.44 ft-lbs. His buddy happens to fly by his position at 500 fps with perfect timing and trajectory so that he is flying parallel to the pellet. He reaches out, grabs the pellet, places it in his CO2 pellet rifle and fires the pellet at 500 fps along exactly the same path. From his perspective he has also added 4.44 ft-lbs of energy to the pellet. From his buddy's perspective however the pellet is now traveling 1000 fps with an energy of 17.76 ft-lbs. From where did this mysterious 8.88 ft-lbs of energy appear and in what form to we find it? :grumpy: