Main variables:
\( \rho \) = Density.
\(m \) = Mass.
\(V \) = Volume.
\( V_{fd} \) = Volume of the displaced fluid.
\(P \) = Pressure.
\(\vec{F} \) = Force.
\( F_B \) = Buoyant force.
\(A \) = Area.
\(P_0 \) = Atmospheric pressure.
\(g \) = Gravitational acceleration.
\(h \) = Height.
\( Q \) = Volume flow rate.
\( v \) = Flow speed.
\(z \) = Height.
When we write \(a\) instead of \(\vec{a}\), we refer to the magnitude of that vector. For instance, \(\vec{a}\) is the acceleration vector, and \(a\) is the magnitude of the acceleration.
Subindex ‘i’ means initial. Subindex ‘f’ means final. For example, \(\vec{v}_i\) represents the initial velocity.
Main Equations:
The density of an object is:
\begin{equation*}
\rho = \frac{m}{V}.
\end{equation*}
Pressure:
\begin{equation*}
P = \frac{F}{A}.
\end{equation*}
Pressure in a fluid of uniform density:
\begin{equation*}
P = P_0 + \rho g h.
\end{equation*}
Buoyant force (Archimedes’ principle):
\begin{equation*}
F_B = \rho_F V_{fd} g.
\end{equation*}
Volume flow rate:
\begin{equation*}
Q = \frac{ \Delta V}{ \Delta t} = A v.
\end{equation*}
Volume flow rate in differential form:
\begin{equation*}
Q = \frac{dV}{dt} = A v.
\end{equation*}
Continuity equation:
\begin{equation*}
A_i v_i = A_f v_f.
\end{equation*}
Bernoulli equation:
\begin{equation*}
P_i + \rho g z_i + \frac{1}{2} \rho v_i^2 = P_f + \rho g z_f + \frac{1}{2} \rho v_f^2.
\end{equation*}