You can do that, but we like to get the answer the way this gentleman described it, because we like to get an answer more readily than by doing the mundane work.

你可以那样做,但是我们喜欢,用这位同学所说的方法来得到结果,因为我们喜欢更简洁地获得结果,而不是通过繁琐的计算

耶鲁公开课 - 基础物理课程节选