If A = 3î + 4ĵ and B = 7î + 24ĵ,the vector

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If $A = 3\hat i + 4\hat j$ and $B = 7\hat i + 24\hat j,$the vector having the same magnitude as $B$ and parallel to $A$ is

A

$5\hat i + 20\hat j$

B

$15\hat i + 10\hat j$

C

$20\hat i + 15\hat j$

D

$15\hat i + 20\hat j$

If $A = 3\hat i + 4\hat j$ and $B = 7\hat i + 24\hat j,$the vector having the same magnitude as $B$ and parallel to $A$ is

$|B|\, = \sqrt {{7^2} + {{(24)}^2}} $ $ = \sqrt {625} $ $ = 25$

Unit vector in the direction of $A$ will be $\hat A = \frac{{3\hat i + 4\hat j}}{5}$

So required vector =$25\left( {\frac{{3\hat i + 4\hat j}}{5}} \right)\,$ $ = 15\hat i + 20\hat j$