Figures and Tables mislocated in compiled document

Question

My figures don't show up in the compiled document in the location that they are in the code. I've tried typing \begin{figure}[h] or \begin{figure}[!h], but the figures still don't show up where I put them in the code.

Here is my code:

 In an effort to prevent this wastage, Dr. Mohammad Kassemi conducted a number of Zero Boil-Off Tank (ZBOT) experiments, which investigated temperature control strategies of a Freon known as perfluoro-n-pentane (PNP)\cite{kassemi2018zero}. ZBOT experimental hardware is shown below.
\begin{figure}
    \centering
    \includegraphics[width = \textwidth]{graphics/ZBOTHardware.png}
    \caption{ZBOT experimental hardware: Test tank (left), full experiment assembly section view (middle), and screen LAD assembly(right)}
    \label{fig:ZBOTHardware}
\end{figure}
The first series of these experiments was ground-based CFD-model validation of tank self-pressurization, and the second series tested a subcooled-jet pressure control strategy in microgravity on the International Space Station. Finally, the third series of experiments introduced a noncondensable gas into the ZBOT to study the effect of pressurant gases on pressure control strategies\cite{kassemiYTVid}.
In the second series of experiments, a subcooled jet was shot into the liquid volume of the tank, decreasing temperature stratification in the propellant and, thus, decreasing the presence of local hot spots where boiling can occur. Additionally, the ullage temperature decreased and the pressure in the tank decreased. An interesting finding during these experiments was that as the pressure in the tank decreased, bubbles formed above and below screens placed in the tank.
\begin{figure}
    \centering
    \includegraphics{graphics/bubbleOnScreen.png}
    \caption{Still frame from ZBOT video data showing the bubbles on the screen and in the volume above (in the orientation) the screen. Large spherical bubbles are present because of the zero-g condition. Screen is not visible.}
    \label{fig:bubblesOnScreen}
\end{figure}
These screens are meant to mimic liquid acquisition devices (LADs), which assist with the separation of the liquid and vapor phases of propellant, and ensure that only liquid propellant is drawn into a rocket engine or into propellant storage tanks\cite{hartwig2014influential}.

Here is the output:

As you can see, the images show up on different pages well after the point where they are in the code. The same problem happens to me with tables.