sans-serifsansmathfonts
We know that kpfonts has a sans-serif math font, but the \mathsf and \symsf seem to use the CM fonts.
\documentclass{article}
\usepackage[bold-style=ISO,sans-style=italic]{unicode-math}
\usepackage{kpfonts-otf}
\begin{document}
Hello world ball, 2022.
\begin{equation}
\mathsf{ABC}\symsf{ABC}
\end{equation}
\end{document}
You should also load newtxtext, for the text fonts. A small correction should be made as well, for \mathsf{\Omega}. Also load bm, which is better than the standard version for \boldsymbol provided by amsmath. You can also use \bm instead of \boldsymbol.
\documentclass{article}
\usepackage{amsmath}
\usepackage{bm}
\usepackage{newtxtext,newtxmath}
\DeclareMathAlphabet{\mathsf}{OT1}{\sfdefault}{m}{n}
\SetMathAlphabet{\mathsf}{bold}{OT1}{\sfdefault}{b}{n}
\begin{document}
Sans serif, no bold: $\mathsf{A}, \mathsf{\Omega}$
Sans serif, bold: $\boldsymbol{\mathsf{A}}, \boldsymbol{\mathsf{\Omega}}$
\end{document}
If the document is going to take the form of a beamer presentation, I recommend you -- or the colleague you're helping to get started -- do two things:
issue the instruction \usefonttheme{professionalfonts} in the preamble, and
load the arev package, which loads the arevtext and arevmath packages.
In my experience, the arev text and math fonts are both a bit darker and more widely spaced than the corresponding CM Sans fonts. I consider both of these features to be significant pluses for the purpose of writing a beamer-based presentation. For beginners in the business of giving presentations, a perennial and near-fatal tempatation is to try to cram too much material into any given slide. A font that's slightly more generously spaced and therefore makes it more difficult to cram too much material into a slide is highly advantageous in this regard. :-)
Another thing I like about the arev math fonts -- however, this is clearly just a personal preference -- is that quite a few of the math-mode alphabetic glyphs actually look "italic" rather than just "slanted". This is quite apparent if one compares \textit{x} (purely slanted) with $x$ (more "italic", not just slanted). Other glyphs that have this distinctly "italic" look in math mode are a, f, i, l, u, v, and w. To repeat what I stated before, though: This is clearly just a personal preference; your preferences may very well be rather different.
A full MWE:
\documentclass{beamer}
\usefonttheme{professionalfonts}
\usepackage{arev}
\begin{document}
\begin{frame}
$\displaystyle abc + \sum_{k=1}^n \int_0^k \sqrt{2} f(x)\,\text{d}x$
\medskip\noindent
\begin{tabular}{@{}lll}
text-mode: & \emph{bcdeghjkmnopqrstyz} & \emph{afiluvwx} \\
math-mode: & $bcdeghjkmnopqrstyz$ & $afiluvwx$
\end{tabular}
\end{frame}
\end{document}
Best Answer
The fonts are different, though it can be hard to tell with sans fonts. Compare: