Vector Algebra Question 14
Question: If $ \mathbf{a}=4\mathbf{i}+6\mathbf{j} $ and $ \mathbf{b}=3,\mathbf{j}+4,\mathbf{k}, $ then the component of a along b is
[IIT Screening 1989; MNR 1983, 87; UPSEAT 2000]
Options:
A) $ \frac{18}{10\sqrt{3}}(3\mathbf{j}+4\mathbf{k}) $
B) $ \frac{18}{25}(3\mathbf{j}+4\mathbf{k}) $
C) $ \frac{18}{\sqrt{3}}(3\mathbf{j}+4\mathbf{k}) $
D) $ (3\mathbf{j}+4\mathbf{k}) $
Show Answer
Answer:
Correct Answer: B
Solution:
- The component of vector $ \mathbf{a} $ along $ \mathbf{b} $ is $ \frac{(\mathbf{a},.,\mathbf{b})\mathbf{b}}{|\mathbf{b}{{|}^{2}}}=\frac{18}{25}(3\mathbf{j}+4\mathbf{k}). $
BETA
