注册应用程序后，运动日志会问你为什么要锻炼。

After you sign up in the app, RunKeeer will ask you why you are exercising.

youdao

但我认为这还是一个很有意思的例子，解释为什么我们要掌握向量的方法去分析运动。

But, still I think it's a very interesting example of why you might want to use vector methods to analyze motions.

youdao

或者是问一个橄榄球运动员——当你在操场上奔跑时，你为什么要往这边跑而不是那边呢，当你在操场上跑的时候？

Or a football player — when you're running down the field, why did you go to this way instead of that way? When you're running down the field?

youdao

Or a football player--when you're running down the field, why did you go to this way instead of that way ? when you're running down the field?

或者是问一个橄榄球运动员--当你在操场上奔跑时，你为什么要往这边跑而不是那边呢,当你在操场上跑的时候？

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