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I am really sorry for the junior question but I have a friend who does not understand this. I have been trying to explain this countless times but he does not understand and is convinced that $(ms^{-1})^2$ is (1) below instead of (2):

  1. $ms^{-2}$.
  2. $m^2s^{-2}$.
  • 5
    Does your friend understand the difference between $(ab)^2$ and $ab^2$?2011-09-13

2 Answers 2

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$(a\cdot b)^2 = (a\cdot b)\cdot(a\cdot b)=a\cdot b\cdot a\cdot b=a\cdot a\cdot b\cdot b=a^2\cdot b^2$

Now set $a=m$ and $b=s^{-1}$.

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Perhaps it will help if you use an example: $m = 4$, $s=2$.