- #1
fluidistic
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Homework Statement
I must derive Torricelli's law.
Homework Equations
[tex]P+\rho gh +\frac{\rho v^2}{2} = \text{constant}[/tex].
The Attempt at a Solution
I chose the origin of the system as being on the surface of the liquid.
I have that [tex]P_0 = P_1+ \frac{\rho v_1^2}{2}[/tex].
But [tex]P_1=P_0+\rho gh[/tex], so the equation is equivalent to [tex]0 = \rho gh +\frac{ \rho v_1^2}{2}[/tex].
Hence [tex]v_1^2=- 2gh[/tex].
I see that I made an error of sign, but I don't know where. The "x-axis"'s positive sense I considered was the one pointing to the ground.
What did I do wrong?
Thanks in advance.