一、用乒乓球巧做支点1.器材:玻璃棒,橡胶棒各两支、乒乓球两只、毛皮、细绸、未拆包的带有塑料膜的香烟一盒、电吹风机等.2.制作、操作过程:(1)用点燃的香烟沿兵乓球大圆的直径烫成两圆孔,大小以玻璃(或橡胶)棒的横截面积为宜(适当紧密).(2)分别用玻璃棒和橡胶棒插入圆孔,用旋进、旋出的方法使乒乓球在玻璃棒9或橡胶棒)的重心处.如图1 1. Use ping-pong as a fulcrum 1. Equipment: two glass rods, two rubber rods, two table tennis balls, fur, fine silk, unopened cigarette packs with plastic film, hair dryer, etc. 2. Production and operation process: (1) Using lighted cigarettes to make two round holes along the diameter of the big table tennis ball, the size of the glass (or rubber) rod is appropriate (appropriately tight). (2) Glass separately Sticks and rubber rods are inserted into the round holes, and the ping-pong balls are placed at the center of gravity of the glass rods 9 or rubber rods by precession and unscrewing. Figure 1