Where's My Kinetic Energy?
My question is very brief but the explanation may be a bit more complex. My question is this: Wherz my kinetic energy??
OK, here is what I am asking about: Let’s say there are two parallel railroad tracks in the desert. I am sitting on one track in a stationary railroad car with a rifle and there is a target on the track in front of me 100 yards away. On the other track is a train coming up behind me at 100 miles per hour. You guessed it, there is a person on this train with a rifle just like mine and a target on the track right next to mine.
At the instant that we are right next to each other, both of us shoot at the target. Which bullet will hit first? The answer is, of course, obvious. The other bullet will hit the target first because it has been imparted with 100 mph of kinetic energy that my bullet doesn’t have.
Now let’s change the location of this scenario to outer space and use light beams instead of
Bullets. I am sitting 10,000 miles from Earth in a spaceship that is stationary relative to Earth. Coming up behind me and to one side is another spaceship traveling 1000 miles per hour. At the instant that we are equidistant from Earth, we each fire a strong beam of light at the Earth. Which beam of light will hit Earth first?
I took a lot of astronomy in college (I majored in G & P) and was taught that the speed of light is constant. According to this notion, light is apparently not effected by kinetic energy. But I also learned that kinetic energy doesn’t simply vanish, it must dissipate or be absorbed in a process such as the action of friction. How could 1000 mph of kinetic energy be imparted to a mechanism that produces a beam of light, but not to the light itself? In short, wherz my kinetic energy??