Question

If magnitude of A vector is 20 root 3 unit and magnitude of B vector is 20 unit and theta is 90 degree . find magnitude and vector of the resultant vector. plz tell me answer

Answer 1

Answer:

A variety of mathematical operations can be performed with and upon vectors. One such operation is the addition of vectors.

Two vectors can be added together to determine the result (or resultant).

given

A = 3 units and B = 4 units let theta be angle between them. and R the resultant vector.

magnitude of R^2= { A^2 +B^2 + 2. A.B. Cos( angle between A and B) }

1= 9 + 16 + 2x 3 x 4 . cos (theta)

so

Cos(theta) = -1 , therefore theta = pi

alternatively -

R = A + B = 1 unit in magnitude

therefore the cosine term must yield a -ve value or the A and B vectors must be opposite to each other and the angle between them must be pi.

the cross product will vanish as the

A X B = A.B. Sin (angle between them) n^ = A.B. sin(pi) =0