2012.02.20 01:50
Newton's fourth law
Let's consider a projectile fired horizontally, and then flying freely. Notice that the horizontal component of the projectile's velocity does not change (because there is no resistance), while the vertical component increases (because of Earth's acceleration). Thus, the total velocity of the projectile increases. Also, notice that the height of the projectile keeps decreasing. But if we fire the projectile at high speed, its height will decrease, but also the Earth - which is curved, not flat - will move away from under it. So if we fire it fast enough, it will never fall (because the Earth will move away from under it so quickly that it won't fall), but it will fly faster and faster (because its speed is constantly increasing). Until it accelerates so much that, wow.
comments:
back to homepage
RSS