Kinematics Question 600
Question: $ \overrightarrow{a}=3\hat{i}-5\hat{j} $ and $ \overrightarrow{b}=6\hat{i}+3\hat{j} $ are two vectors and $ \overrightarrow{c} $ it’s a vector such that $ \overrightarrow{c}=\overrightarrow{a}\times \overrightarrow{b} $ then $ |\overrightarrow{a}|:|\overrightarrow{b}|:|\overrightarrow{c}| $
Options:
A) $ \sqrt{34}:\sqrt{45}:\sqrt{39} $
B)$ \sqrt{34}:\sqrt{45}:39 $
C) $ 34:39:45 $
D)$ 39:35:34 $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] We have $ \vec{a}\times \vec{b}=39\vec{k}=\vec{c} $
$ \text{Also}|\vec{a}|\text{ =}\sqrt{34},|\vec{b}|=\sqrt{45},\text{}|\vec{c}|\text{ =}\text{39 ;} $
$ \therefore |\vec{a}|\text{ :}|\vec{b}|\text{: }|\vec{c}|=\sqrt{34}:\sqrt{45}:39. $
