SATII物理专题分析 Vector Addition.

　　SAT考试是美国高中生进入美国大学的标准入学考试，包括SAT1和SAT2。SAT2是专项测验，有数学、物理、化学、生物、外语等，大部分为选择题，是可以选科的。今天我们来学习SATII物理专题分析 Vector Addition，希望对大家的复习有所帮助。

　　There are bound to be several questions on SAT II Physics that involve vector addition, particularly in mechanics. The test doesn’t demand a very sophisticated understanding of vector addition, but it’s important that you grasp the principle. That is, you won’t be asked to make complicated calculations, but you will be expected to know what happens when you add two vectors together.

　　The easiest way to learn how vector addition works is to look at it graphically. There are two equivalent ways to add vectors graphically: the tip-to-tail method and the parallelogram method. Both will get you to the same result, but one or the other is more convenient depending on the circumstances.

　　Tip-to-Tail Method

　　We can add any two vectors, A and B, by placing the tail of B so that it meets the tip of A. The sum, A + B, is the vector from the tail of A to the tip of B.