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تسجيل

Equilibrium

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-84

2025-11-04

472

Pierce a disk of cardboard with two holes, one at the center, and the other near the edge. Suspend it on a pin P (Fig. 1), from the hole near the edge

Fig. 1

and it will take the position a, such that the center will lie in the vertical line below P. If the disk is moved, the center of gravity will be raised, and the disk will tend to return to its first position. This condition is that of stable equilibrium.

If the disk is placed in position b, and a slight push is given to it, the center of gravity will be lowered; and the disk will tend to go farther from its position. This is the condition of unstable equilibrium.

Place the disk in position c. Set it in motion, and the center of gravity neither rises nor falls, and the disk comes to rest in one position as well as another. This is the condition of neutral equilibrium.