[tex]P_1 + \frac{1}{2} \rho (v_1)^2 + \rho g h_1 = P_2 + \frac{1}{2} \rho (v_2)^2 + \rho g h_2 [/tex](adsbygoogle = window.adsbygoogle || []).push({});

In this equation (and regular energy equations for that matter) is g= 9.8 or -9.8 m/s^2 ?

To make sense mathematically I believe it has to be 9.8 or else pressure and velocity would increase as a fluid increases its height. I think my textbook needs to define when g is negative and when it is positive can get confusing sometimes. In kinematic equations you can pick a reference frame and set it positive or negative yourself but in energy equations it can get confusing.

For example [tex] W_{gravity} = - \Delta PE [/tex] and also [tex] \Delta PE = mg \Delta y [/tex] . If it weren't for my teacher showing me that work was the magnitude of F X magnitude of distance X cosine of lesser included angle (which my book neglects to mention) I'd be completely confused.

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# Homework Help: Potential Energy and Bernoulli

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