Is g Positive or Negative in Bernoulli's Equation?

[Skomatth]

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

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 W_{gravity} = - \Delta PE and also \Delta PE = mg \Delta y . 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.

 

[Doc Al]

In common usage g is always the magnitude of the acceleration due to gravity; it is a positive quantity (e.g., 9.8 m/s^2). Thus the acceleration due to gravity is g, downward.

 

[wais]

In this equation, g is typically taken to be positive 9.8 m/s^2, representing the acceleration due to gravity. This is the standard convention used in most physics and engineering problems. However, it is important to note that the choice of positive or negative g may depend on the specific problem and the coordinate system being used. In some cases, it may be more convenient to use negative g, for example when dealing with objects moving in a downward direction. It is always important to clearly define the direction and sign convention for g in any problem to avoid confusion.

In the potential energy and Bernoulli equation, g is used to account for the change in gravitational potential energy as a fluid moves from one point to another. The direction and sign of g will depend on the coordinate system being used and the direction in which the fluid is moving. In this equation, g is typically taken to be positive when the fluid is moving in the direction of increasing height, and negative when the fluid is moving in the direction of decreasing height. This ensures that the overall change in potential energy is correctly accounted for.

It is important to carefully consider the direction and sign conventions for g in any energy equation to ensure accurate and consistent calculations. As you mentioned, it can get confusing at times, but having a clear understanding of the conventions and how they apply to different scenarios can help avoid confusion and errors. It is always a good idea to clarify these conventions with your teacher or textbook if you are unsure.