A) 20 m
B) 7.2 m
C) 5.0 m
D) 4.5 m
Correct Answer: B
Solution :
Here, \[A=4\vec{i}+10\vec{j}\] \[\therefore \] \[|A|=\sqrt{{{(4)}^{2}}+{{(10)}^{2}}}=\sqrt{116}\] Now, according to question, \[A=8\vec{i}+n\,\vec{j}\] \[|A|=\sqrt{{{(8)}^{2}}+{{(n)}^{2}}}\] \[\sqrt{116}=\sqrt{64+{{n}^{2}}}\] \[n=\sqrt{116-64}=7.2\,m.\]You need to login to perform this action.
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