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Grade 11Vectors

The resultant of two vectors P and Q is R. If Q is double then new resultant is perpendicular to p vector. Find out the angle of new resultant vector with the doubled vector or 2q.

Profile image of Hemant yogi
9 Years agoGrade 11
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1 Answer

Profile image of ric
9 Years ago
it is given that R= vector P + vector Q
let new resultat be R’ 
so when Q is doubled then R perpendicular P.
solution: vector P + vector Q = Vector R
as R’ is perpendicular to  P
there dot product wil be zero
(vector P) . (vector 2Q)= 0
so cos theta= vector P+vector2Q/2Q
  theta = cos-1P+ 2Q/2Q