论文部分内容阅读
例1如图1所示,长为L,内壁光滑的直管与水平地面成30°角固定放置,将一质量为m的小球固定在管底,用一轻质光滑细线将小球与质量为M=km的小物块相连,小物块悬挂于管口,现将小球释放,一段时间后,小物块落地静止不动,小球继续向上运动,通过管口的转向装置后做平抛运动,小球的转向过程中速率不变(重力加速度为g)。(1)求小物块下落过程中的加速度大小;(2)求小球从管口抛出时的速度大小;(3)试证明小球平抛运动的水平位移总小于2~(1/2)/2L。
Example 1 As shown in Figure 1, the length of L, smooth straight wall with a horizontal angle of 30 ° fixedly placed, will be a mass of m ball fixed to the bottom of the tube, with a light smooth thin ball And the mass is M = km connected to the small pieces of small pieces suspended in the nozzle, the ball is now released, after a period of time, the small pieces of the floor standing still, the ball continued upward movement through the nozzle after the steering device flat Throwing motion, the ball does not change its velocity during the steering (gravitational acceleration is g). (1) Seeking the acceleration of the small objects in the process of falling; (2) Seeking the velocity of the ball when it is thrown from the nozzle; (3) Proving that the horizontal displacement of the flattening and throwing motion of the ball is less than 2 ~ (1/2 ) / 2L.