一、动能定理的表述合外力做的功等于物体动能的变化.(这里的合外力指物体受到的所有外力的合力,包括重力).表达式为W=ΔEK动能定理也可以表述为:外力对物体做的总功等于物体动能的变化.实际应用时,后一种表述比较好操作.不必求合力,特别是在全过程的各个阶段受 First, the expression of kinetic energy theorem The work done by the external force is equal to the change of the kinetic energy of the object (where the combined external force refers to the resultant force of all the external forces on the object, including gravity.) The expression is W = ΔEK kinetic energy theorem can also be expressed as: The total work done by the object is equal to the change of the kinetic energy of the object. In practical application, the latter is better for operation and does not need to work together, especially in all stages of the whole process.