Vectors Question 165
Question: The value of $ (\overrightarrow{A}+\overrightarrow{B}),\times (\overrightarrow{A}-\overrightarrow{B}) $ is
[RPET 1991, 2002; BHU 2002]
Options:
A) $ 14\hat{i}-38\hat{j}+16\hat{k} $
B) $ 4\hat{i}+4\hat{j}+6\hat{k} $
C) $ 21\hat{i}+4\hat{j}+4\hat{k} $
D) $ -14\hat{i}+34\hat{j}-16\hat{k} $
Correct Answer: A $ \vec{\tau }=\vec{r}\times \vec{F}=(7\hat{i}+3\hat{j}+\hat{k}),(-3\hat{i}+\hat{j}+5\hat{k}) $ $ \vec{\tau }=,| \begin{matrix} {\hat{i}} & {\hat{j}} & {\hat{k}} \\ 7 & 3 & 1 \\ -3 & 1 & 5 \\ \end{matrix} | $ $ =14\hat{i}-38\hat{j}+16\hat{k} $
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Answer:
Solution:
BETA
