Question

The direction of a vector is $\overrightarrow{A}$ reversed. What are the values of $\Delta \overrightarrow{A}$ and $\Delta \left|\overrightarrow{A}\right|$?

• A. $+2\overline{A},0$
• B. $+\overline{A},0$
• C. $-2\overline{A},0$
• D. $-\overline{A},0$

Answer 1

The correct option is A $+2\overline{A},0$

$\overrightarrow{A_{initial}}=\overrightarrow{A}$

$\overrightarrow{A_{final}}=-\overrightarrow{A}$

$\Delta \overrightarrow{A}=\overrightarrow{A_{final}}-\overrightarrow{A_{initial}}=\overrightarrow{A}-(-\overrightarrow{A})=+2\overrightarrow{A}$

$|\Delta \overrightarrow{A}|=|\overrightarrow{A_{final}}|-|\overrightarrow{A_{initial}}|=\overrightarrow{A}-\overline{A}=0$