1.1机械功课件-2021-2022学年高一下学期物理鲁科版（2019）必修第二册

1.1机械功 鲁科版（2019）必修二 《鲁科版物理必修1（2019）》 历城二中•高一物理组 导入新课 实践中： 科里奥利： 把作用于物体上的力和受力点沿力的方向的位移的乘积叫做"力的功” 功的概念起源于早期工业发展的需要 用机器举起的物体的重量与路程的乘积来量度机器的功效 工程师们需要一个比较蒸汽机效能的办法 Life is not about waiting for the storm to pass, its about learning to dance. <鲁科版必修1> Life is not about waiting for the storm to pass, its about learning to dance. 交流讨论： 1.回顾初中知识：如何判断一个力是否做功？ 1.机械功的含义 ——力在空间上的积累 Life is not about waiting for the storm to pass, its about learning to dance. <鲁科版必修1> Life is not about waiting for the storm to pass, its about learning to dance. 交流讨论： 2.某人用一定的力斜拉行李箱移动时，拉力对箱子做功了吗？ 当力与位移成一定夹角时，如何求做功的大小？ 1.机械功的含义 Life is not about waiting for the storm to pass, its about learning to dance. <鲁科版必修1> Life is not about waiting for the storm to pass, its about learning to dance. 交流讨论： 3.若把力的方向改为与水平方向夹角斜向下，力F做的功是多少？ 通过以上问题，你以为，功有方向吗？ 1.机械功的含义 力做的功仍为，所以功不具有方向性。功是标量。 Life is not about waiting for the storm to pass, its about learning to dance. <鲁科版必修1> Life is not about waiting for the storm t