Question

Vectors A and B are in the xy plane and their scalar product is 20.6 units.?
If A makes a 27.8 angle with the x axis and has magnitude A= 14.8 units, and B has magnitude B= 29.0 units, what can you say about the direction of B?

Answer 1

A B costheta = 20.6
14.8*29.0*costheta = 20.6
costheta = 0.048
theta = 87.2 degrees is the angle between A and B. The angle of B with the x axis could be 27.8 + 87.2, or 27.8 - 87.2