高中通常用惯性球做动量定理演示实验(如图1所示),快速拉动绳端时α处断开,缓慢拉动绳端时b处断开。但因为断开过程都是瞬间完成的,作用时间都很短,力对小球的冲量Ft很小,球的动量变化△mv也很小,从直观上看不出球的动量变化,所以在利用此实验 High school usually uses the inertial ball as the momentum theorem to demonstrate the experiment (as shown in Figure 1). When pulling the rope end quickly, α is disconnected, and when the rope end is slowly pulled, b is disconnected. But because the disconnection process is completed instantaneously, the action time is very short, the impulse Ft of the ball to the ball is very small, the momentum of the ball changes △mv is also very small, intuitively can not see the ball momentum changes, so in Use this experiment