答案1
对于以后的问题,请提供 MWE 并阅读蒂克兹。您可以使用下面的一段代码来开始。
\documentclass[border=3.5mm]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[inner sep=5pt]
\node[circle, draw=black] (A) at (0,0) {};
\node[circle, draw=none] (B) at (3,0) {};
\node[circle, draw=none] (C) at (0,-3) {};
\draw [->,dashed] (A) -- node[above] {\tiny Movement of train} (B);
\draw [->,dashed] (A) -- node[above, rotate=90] {\tiny Movement of ball} (C);
\draw[red,thick] (A) -- (2,-2) node[below right] {\tiny Observed effective Movement of ball (D2)} -- (4,0);
\end{tikzpicture}
\end{document}