Sometimes they give you the speed in miles per hour, kilometers per year, pounds per square foot.

有时候速度的单位是英里/小时,千米/年,英磅/平方米

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I agree, but I want the speed in meters per second.

我同意,但我希望速度以米每秒为单位

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We divide that by the mass, so 0.12 kilograms, that's the mass of a regulation baseball for the major leagues, and the velocity of the baseball is 42 meters per second. So, we can cross out our units doing our unit analysis.

我们用质量来除它，质量为0，12千克，这是大多数联赛规定的棒球质量,棒球的速度为42米每秒,所以，我们可以消去单位,来做单位分析。

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