Ok, I know that, using a FBD, one is susposed to use [tex] \sum F = m a [/tex](adsbygoogle = window.adsbygoogle || []).push({});

My question is what order do you put the forces that [tex] \sum F [/tex] equal

An example might help me explain my question.

Lets take a block of wood that is supported by a string. The only forces acting on it are [tex] mg [/tex] and [tex] T [/tex]

So...

[tex] \sum F = ma [/tex]

[tex] T - mg = ma [/tex]

or

[tex] mg - T = ma [/tex].

I know if [tex] a = 0 [/tex] it does not matter, but how does one decide what order to put th forces in when there is acleration?

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# Homework Help: Question Concerning F=ma and FBDs.

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