How Do You Graphically Solve Vector Displacement Problems?

[veloix]

Homework Statement

Each of the displacement vectors and shown in Figure P1.38 has a magnitude of 3.00 m. Find the following values graphically. Report all angles counterclockwise from the positive x axis.

Figure P1.38

(a) A+B=?
magnitude m

60°
(b) A - B=?
magnitude
m

°
(c) B-A=?
magnitude m

.°
(d) A- 2B
magnitude m
°

Homework Equations

C=A+B C=B+A C= A+ (-B) maybe X= mcos(theta) Y=msin(theta)

The Attempt at a Solution

Ive been working on this problem for long time now, these vector properties are confusing, so far i manage to come up with some diffrent ways to get the resulant for part A but i don't know if I am doing it right. first thing i try to connect A to B but extending the tail towards the head of B, then i mesuared the resultant, but got wrong answer. Same thing when I went from B to A, I don't know if connecting them right. I really need some one to shine some light on this one. When I do extend to B from A it turns out to be a Eqaultrail triangle, so the angle must be 60 deg where it meets.

 

[learningphysics]

If you draw the 3rd side of the triangle formed by the two sides you've drawn on the picture... ie draw a vector from the head of B to the head of A, what vector is that?

 

[veloix]

turns out with the help of a niffty program, the resultant goes straight in the middle of the two vectors when you have A+B. This forms a pallrelagram with an angle of 60 deg at the end. I figure it out for myself, but I appreicate the response. I just stay with it for whole time, but sheer luck it started fitting together. I was able to answer all the parts.