Physics help!?

Question

Vector A points in the negative y direction and has a magnitude of 7 units. Vector B has twice the magnitude and points in the positive x direction. Find the direction and magnitude of the following vectors.

(a) A + B
___________
___________ ° (counterclockwise from the +x-axis)

(b) A - B
_________
_________° (counterclockwise from the +x-axis)

(c) B - A
___________
___________° (counterclockwise from the +x-axis)

Answer 1

Me do no homework
Me explain...

1. Break all components into x and y components
Ax= Acos(a)
Ay=Asin(a) or something like that

2. Add them algebraically
Rx=Ax+Bx+Cx...
Ry=Ay+By+Cy...

3. Find the magnitude of the resultant
R=sqrt(Rx^2 +Ry^2)
4. compute the angle r
r=arctan(Ry/Rx)

so A+B=
Rx=14
Ry=-7
R=sqrt(14^2 +7^2)=15.7
r=atan(-7/14)= -26.6

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