Vectors



Q. Let the angle between two nonzero vectors A and B be 120° and its resultant be C.



a) C must be equal to

b) C must be less than

c) C must be greater than

d) C may be equal to



the answer in the book is (c)... is that correct ? n show me the initial steps ....pls..

What problem R U facing in this question?

Resultant of A,B is given by-

Now,

Or,

Hope U get it.

but isnt the magnitude of

(A-B) = root( A square + B square + 2AB cos 60 ) ,   will be btween and , WHICH IS 180 -120= 60

 

             = root ( A square + B square +AB )



AND as C = root ( A square + B square - AB )

C < (A-B)



am i wrong ?