1 仪器结构 仪器结构见附图(1),(2)。 1是斜槽,用来发射小球。2是小钢球,其半径为R(用千分尺测得)。3是重锤用来确定Y轴方向,不用时可将它挂在斜槽下方(图1)。4是竖直板。5是百叶窗式活页,它是用宽为4～5厘米,长适当的三夹板或塑料板(白色)做成,将它用金属小活页通过铆钉与竖直木板紧密固连,但可灵活折起与竖直板面垂直(图 1 Instrument Structure The instrument structure is shown in Figures (1) and (2). 1 is a chute for launching small balls. 2 is a small steel ball whose radius is R (measured with a micrometer). 3 is a weight used to determine the direction of the Y axis, when not in use it can be hung under the chute (Figure 1). 4 is a vertical plate. 5 is a shutter-type leaflet, which is made of plywood or plastic plate (white) with a width of 4 to 5 cm and an appropriate length, and it is tightly fastened to a vertical plank with a metal loose leaf, but it can be folded flexibly. Vertically perpendicular to the vertical plate (Figure