Physics Two Dimensional Motion Question 135
Question: The x and y components of $ \overrightarrow{\text{A}} $ are 4 m and 6 m, respectively. The x and y components of $ (\overrightarrow{A}+\overrightarrow{B},) $ are 10 m and 9 m respectively. The magnitude of vector B is:
Options:
A) 19 m B)$ \sqrt{27} $ C) $ \sqrt{45} $ D)$ \sqrt{50} $
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Answer:
Correct Answer: C
Solution:
[c] $ \text{\vec{A} = }4\hat{i}+6\hat{j}. $ If $ {{\text{B}} _{\text{x}}} $ and $ {{\text{B}} _{\text{y}}} $ are the components of vector along x and y axes, then $ \text{4+}{{B _{x}}\text{=10, }\
Therefore {{B _{x}}=6 $ Also$ \text{6+}{{B _{y}}\text{=9, }\
Therefore {{B _{y}}=3. $
$ \text{Thus, B},\text{=}\sqrt{\text{B} _{x}^{2}\text{+B} _{y}^{2}}=\sqrt{6^{2}+3^{2}}=\sqrt{45}. $