Question

obtain the formula for magnitude of the resultant vector using low of parallelogram a river is flowing 6kg per hour a man swims across it with velocity 9km per hours. find the resultant velocity of man?​

Answer 1

Answer:

Note: vectors are shown in bold. scalars are shown in normal type

The diagram above shows two vectors A and B with angle p between them.

R is the resultant of A and B

R = A + B

This is the resultant in vector

R is the magnitude of vector R

Similarly A and B are the magnitudes of vectors A and B

R = √(A2 + B2 2ABCos p) or [A2 + B2 2ABCos p]1/2

To give the direction of R we find the angle q that R makes with B

Tan q = (A Sin p)/(B + A Cos q)

A vector is completely defined only if both magnitude and direction are given.