3.3.1: The Units of Angular Momentum
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If you look at the equation
\(\ l=d p\)
where \(\ l\) is angular momentum, \(\ d\) is the lever arm to a moving particle, and \(\ p\) is the magnitude of the momentum of that particle, you can figure out the units of angular momentum. \(\ d\) has dimensionality of length, of course, and as we worked out in Section 3.2.1, the dimensionality of momentum is mass times length divided by time. Thus, angular momentum has dimensionality mass times length squared divided by time. The SI unit for angular momentum doesn’t have a special name; it’s just \(\ \mathrm{kg} \mathrm{m}^{2} \mathrm{~s}^{-1}\).