\[\renewcommand{\u}[1]{\boldsymbol{\mathsf{#1}}} \renewcommand{\b}[1]{\boldsymbol}\]

Elementary Rigid Body Motion - Basic Notation

We denote quantities having units in bold face using Times New Roman font. For example, we denote position vector as $\boldsymbol{X}$, the velocity vector as $\boldsymbol{V}$, the acceleration vector as $\boldsymbol{A}$, etc.

• Times New Roman $X_i$
  • $X_i$ is just a real number
• Bold, Times New Roman $\boldsymbol{X}$ is a vector/linear-operator (“tensor”) etc.,
  • $\boldsymbol{X}=X_{i}\boldsymbol{E}_i$,
  • $\boldsymbol{X}=X_{ij}\boldsymbol{E}_i\otimes \boldsymbol{E}_j$
• Bold, Sans Serif $\mathsf{X}$
• Bold, Sans Serif
  • $\u{X}=(X_i)_{i=1,2,3}$
  • $\u{X}=(X_{ij})_{i,~j=1,2,3}$

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