Answer:
B= -40
The negative sign indicates the reverse direction to that of vector A.That is it is in the third quadrant.
Explanation:
Th resultant vector is obtained by adding the two vectors A and B
A + B= AB
25 + B= -15
25+ 15= -B
-B = 40
B= -40
Vector B has a magnitude of 40 and points in the opposite direction to that of vector A. The negative indicates the opposite direction.
When we reverse the vector B for adding we place a negative sign with the magnitude.
A vector is quantity defined by magnitude and direction. If the direction is left out it becomes a scalar.
