Motion in a Plane - Result Question 14

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16. The angle between two vectors of magnitude 12 and 18 units when their resultant is 24 units, is

======= ####16. The angle between two vectors of magnitude 12 and 18 units when their resultant is 24 units, is

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/motion-in-a-plane/motion-in-a-plane—result-question-14.md (a) $63^{\circ} 51^{\prime}$

(b) $75^{\circ} 52^{\prime}$

(c) $82^{\circ} 31^{\prime}$

(d) $89^{\circ} 16^{\prime}$

[1999]

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Answer:

Correct Answer: 16. (b)

Solution:

  1. (b) We know that, $R^{2}=A^{2}+B^{2}+2 A B \cos \theta$ $(24)^{2}=(12)^{2}+(18)^{2}+2(12)(18) \cos \theta$

$\cos \theta=\frac{108}{432} \Rightarrow \theta=75^{\circ} 52^{\prime}$