动能定理的一种表述为:“物体动能的变化等于外力对物体所做的总功”。表达式为W_总=1/2mv~2-1/2mv_0~2或W_正+W_负=1/2mv~2-1/2mv_0~2如果物体在运动的过程中初、末速度的大小相等(也可为0),则可得W_正=-W+_负由于动力对物体做正功,阻力做负功,则可由上式得W_动=-W_阻①即如果物体在运动的过程中初、末速度的大小相等(也可为0),则动力对物体做的功在数值上等于阻力对物体做 A statement of the kinetic energy theorem is: “The change in the kinetic energy of an object is equal to the total work done by an external force on an object.” The expression is W_ total = 1 / 2mv ~ 2-1 / 2mv_0 ~ 2 or W_positive + W_negative = 1 / 2mv ~ 2-1 / 2mv_0 ~ 2 If the object is in motion during the beginning and end of the speed The same size (also can be 0), you can get W_ 正 = -W + _ negative Since the power to do positive work on the object, the resistance to do negative work, can be obtained by the above equation W_ move = -W_ resistance ① that if Objects in the process of movement early, the end of the speed of the same size (also can be 0), then the power of the object to do the work is equal to the value of resistance to the object to do