Roger N. answered 09/16/21
. BE in Civil Engineering . Senior Structural/Civil Engineer
Solution:
A vector starts at point A (5, -4) or ( x1, y1) and ends at point B (0, -8) or at ( x2, y2) . What is the vertical component of the vector?
The vertical component of the vector Vy is simply y2 - y1 = -8 -(-4) = -8 +4 = -4 note the negative sign indicate that the vector moving from point A to B is 4 units down , if the vector was moving from B to A then Vy = y1-y2
= -4 -(-8) = -4+8 = +4 and the positive sign indicates that the vector is moving 4 units up. This makes sense because point B is below point A on a cartesian system of axes. Please remember that a vector in space has both a magnitude and a direction that must be indicated by an arrow with vector tail at the start point and and vector head where the arrow is at the end point.