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Name: Rocky
Status: student
Age: 15
Location: N/A
Country: N/A
Date: 2000-2001

When the planets orbit around the sun, the sun has a gravitational pull so they don't go flying off into space. With the power of the sun's gravitational pull, why don't the planets just come crashing into it?

There is a nice balance between the direction change due to the gravitational attraction, and the motion of the object. Think of from events you know on earth. Go up on a mountain. Toss a rock. It lands a little bit down range. Now throw a rock. It goes further down range. Get a gun and shoot the rock. It goes further yet. Each second the rock was in the air, though, it was falling toward the earth, and the earth caught it. Now, what would happen if you threw the rock so hard, that it would fall at the same pace as the earth curves out from underneath it. It would fall the entire time, but instead of hitting the earth, it would just keep on missing it, and fall around the earth. That is the idea behind orbital motion.

Nathan A. Unterman

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