一个运动学结论的重要应用

• 作 者: 张永武
• 机 构: 山东省沂水县第二中学,
• 出 处: 新高考(物理化学生物)
• 发表日期: 2008年09期
• 关键词: 匀减速直线运动 电场力 匀强电场 动能定理 匀加速直线运动 带电粒子 量大小 恒力 牛顿第二定律 持续时间

一、结论的推导结论一质点以加速度a_1由静止开始做匀加速直线运动,时间t后以加速度a_2同直线做匀减速运动,又经时间t后回到出发点,则a_1、a_2的大小关系为a_2=3a_1.证明运动过程如图1所示,A到B过程的加速度大小为a1;BCA′段的加速度为a2,则在A到B的过程中s=21a1t2.在BCA′过程

First, the conclusion of the derivation of a conclusion of a mass point with the acceleration a_1 from the static start uniform acceleration linear motion, after the time t with the acceleration a_2 with a straight line to do a uniform deceleration movement, and after time t back to the starting point, then the size relationship of a_1, a_2 is A_2=3a_1. Prove that the motion process is as shown in Fig. 1. The acceleration of A to B is a1; the acceleration of BCA’ is a2, then in the process of A to B, s=21a1t2. In BCA’ process