To get your attention, I'll ask a science question.
If a bullet is fired from a gun (parallel to the ground), and a second bullet is dropped from the same height, which bullet will hit the ground first? (Assuming the ground is perfectly level and the bullet fired from the gun doesn't hit anything first)
If you (like I) you watched Bugs Bunny as a kid, you might think that bullet fired from a gun would travel at a level height until it ran out of speed, and then fall to the ground. (A lot of stuff in Bugs Bunny was really funny on a scientific level, but I digress). The fact of the matter is, the bullets will hit the ground at the same time. The path of a bullet, if allowed to travel unobstructed, is actually a curve, not a straight line.
In college, I had to study a lot of physics and a lot of math. I was very fortunate because my first job was in the field of Medical Physics, so I actually got to use some mathematics and physics in real life, and I have an appreciation for science and scientists. I am by no means an expert, but at some level I have at least a basic understanding.
I've been troubled many times because many people think science and religion are at odds with one another. One of my long standing beliefs has been that if scientists and religious folks are honestly seeking truth....then they will both arrive at the same conclusion. Many times I watch for scientific breakthroughs that confirm statements that are in the Bible. A few years ago, I had a high school physics teacher reference a verse in the Bible that amazed me. I'll tell you the verse and why it is so amazing in a minute, but its going to take some discussion to get there.
The reason that the bullets hit the ground at the same time is because of gravity. Under Newton's Theory of Gravity, it can be described mathematically as
The m1 and m2 are the masses of the two object being studied, r is the distance between them and G is the gravitational constant. (Sorry, had to get geeky there for a second.) In the case of a bullet, m1 might be the mass of the bullet, m2 would be the mass of the earth, r would be the height that the bullet was at when it started. As you might notice, the fact that the bullet is traveling at a high rate of speed has no effect in the equation.
The fact that the two bullets hit the ground at the same time surprises many folks. (I know a certain middle school science teacher that subscribes to the Bugs Bunny theory of gravity.) I was explaining this to my son and I demonstrated it by doing this simple little experiment.
Take two tennis balls, or any other kind of ball that wont hurt anything. Set one on a table, hold the other at the same height as the table. Push the ball on the table off as hard as you want to, but try to drop the one in your hand at the moment the first one leaves the table. You will find that no matter how hard you push, the balls will hit the floor at the same time.
Newton figured that out a long time ago. He understood the world he lived in....as far as he knew. The next post will expand on that just a touch....
2 comments:
This works at low velocities, and certainly in a vacuum.
At higher velocities, turbulence becomes a problem. On average, both bullets will hit the ground at the same time, but the actual times of the dropped bullet will vary less than the actual times of the fired bullet (i.e., there's more deviation with the fired bullet).
Just like in school, I'm ignoring the factors that really complicate the problem. Looking at the effect of gravity alone, the bullets would hit the ground at the same time true?
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