Vectors 5i + 8j and 2i + 7j are added. magnitude of sum of these vector is

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3-1.Vectors

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The vectors $5i + 8j$ and $2i + 7j$ are added. The magnitude of the sum of these vector is

A

$\sqrt {274} $

B

$38$

C

$238$

D

$560$

Solution

(a) Sum of the vectors $\overrightarrow R = 5\hat i + 8\hat j + 2\hat i + 7\hat j$$ = 7\hat i + 15\hat j$

magnitude of $\overrightarrow R = \,|\overrightarrow R |\, = \sqrt {49 + 225} $$ = \sqrt {274} $

Standard 11

Physics

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