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SCIENCE OF TOPS
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| Why does a top spin? | |
| Tops spin because of the basic laws and principles of physics. |
| Inertia | The tendency of matter to remain at rest (or keep moving in the same direction) unless affected by some outside force or forces. When you wind up a top, you are storing energy in it. As the top is thrown, the energy is slowly released and the itertia keeps the top moving until acted upon by outside forces. In the case of the top, these forces are gravity and friction. |
| Gravity | The force that tends to draw all bodies in the earth's sphere toward the center of the earth. |
| Friction |
The resistance to motion of surfaces that touch. In the spinning top there are two types of friction: direct friction of the tip with the spinning surface and air friction with the surface of the top. The sharpness of the tip, the smoothess of the spinning surface, and smoothness of the top's surface determine the amount of friction the spinning top will encounter. The less friction, the longer the spin. |
| Centrifugal Force | Forces tending to make rotating bodies move away from the center of rotation. This principle states that a body (the top) rotating rapidly about its axis will tend to resist outside influences (gravity). Actually, a top remains upright because centrifugal force pulls inward on the top, keeping the vertical axis of the top perpendicular to the horizontal axis of the ground. |
| As the spinning top slows down, friction and gravity try to tip it over. These forces are resisted by the top's inertia. As the top continues to slow, the crown of the top begins to tip at an angle. The crown moves as it travels in circles and rotates on its axis trying to right itself. This is call precess. As the speed is slowed further by gravity and friction, the top will continue to precess until such time as gravity and friction outweigh the inertia and the top topples and falls. |
