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Find a Vector of Magnitude 4 Units Which is Parallel to the Vector √ 3 ^ I + ^ J

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Question

Find a vector of magnitude 4 units which is parallel to the vector \[\sqrt{3} \hat{i} + \hat{j}\]

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Solution

Let \[\vec{a} = \sqrt{3}\hat{i} + \hat{j}\]
Then,
\[\left| \vec{a} \right| = \sqrt{\left( \sqrt{3} \right)^2 + 1} = \sqrt{3 + 1} = \sqrt{4} = 2\]
A unit vector parallel to \[\vec{a}\] = \[\hat{a} = \frac{\vec{a}}{\left| \vec{a} \right|} = \frac{1}{2}\left( \sqrt{3}\hat{i} +\hat{j} \right)\]

Hence, Required vector = \[4 \hat{a} = 4 \times \frac{1}{2}\left( \sqrt{3}\hat{i} +\hat{j} \right) = 2\sqrt{3} \hat{i} + 2 \hat{j}\]
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Chapter 22: Algebra of Vectors - Exercise 23.4 [Page 42]

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R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12
Chapter 22 Algebra of Vectors
Exercise 23.4 | Q 3 | Page 42

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