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Grade 11General Physics

If the resultant of two vectors a and b shown in figure is √7b.The value of b/a is

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Profile image of Yuvraj singh
8 Years agoGrade 11
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1 Answer

Profile image of Arun
ApprovedApproved Tutor Answer8 Years ago
Dear Yuvraj
 
Resultant R² = a² + b² + 2ab cos 60°
[sqrt(7) *b]² = a² + b² + ab
7 b² - b² = a² +ab
6 b² - a² = ab
6 (b/a) - (a/b) = 1
6t - 1/t = 1
6 t² -t -1 = 0
(3t+ 1) ( 2t -1) = 0
Hence t = -1/3 or 1/2