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一、结论的提出例1如图1所示,质量M,长L的木板A以某一速度在光滑的水平面上向右运动.现将质量为m的物块B(可视为质点)轻轻放在A的右端,当B滑到A的左端时恰能与A相对静止,此时测得物块对地发生的位移为S.若A、B间的滑动摩擦力恒为f,求这一过程中A、B构成的系统产生的热量.解析从B放到A上到两者相对静止,A、B间的摩擦力对A做了负功,使A向右减速,对B做了正功,使B向右加速,如图所示.依据能量守恒定律,系统产生的热量应
First, the conclusions of the proposed Example 1 As shown in Figure 1, the mass M, length L of wood A to a certain speed in the smooth horizontal plane to the right movement now mass m block B (which can be regarded as particle) light Lightly on the right end of A, when B slides to the left of A, it can be relatively quiescent with A. At this time, the measured displacement of the block to ground is S. If the sliding friction between A and B is constant f, In this process, the heat generated by system A and B is analytically analyzed from B to A. The friction between A and B is negative to A, so that A decelerates to the right and B to B A positive work, so B to accelerate to the right, as shown in Figure. According to the law of conservation of energy, the system should generate heat