
#1
Aug2807, 09:57 PM

P: 27

1. The problem statement, all variables and given/known data
Vector A has a magnitude of 11 and points in the positive xdirection. Vector B has a magnitude of 22 and makes an angle of 32 degrees with the positive xaxis. What is the magnitude of Vector A minus Vector B? 2. Relevant equations 3. The attempt at a solution 



#2
Aug2807, 10:00 PM

HW Helper
P: 4,125

Can you describe where you're getting stuck and what you tried?




#3
Aug2807, 10:01 PM

P: 27

I also have another question whereas it states: Use the method of components to find the magnitude and direction of the vector sum R1 where R1= A + B. The Vector A= 15.2 m at an angle alpha= 180 degrees from the positive horizontal axis, and Vector B = 17.2 m at an angle Beta= 41.3 degrees from the positive horizontal axis. Answer in meters. Answer in units of m.
What is the angle, theta 1, from the positive horizontal axis of the vector sum, R 1? What is the magnitude of the vector difference R 2 where R 2= Vector A  Vector B? What is the angle, theta 2, of the resulting vector? What is the magnitude of the vector difference R 3 where R 3= B  A? What is the angle, theta 3, of the resulting vector? 



#4
Aug2807, 10:02 PM

P: 27

Require Help. 



#5
Aug2807, 10:05 PM

P: 1,295

draw a llgm with two vectors A and B,
you have found one diagonal, just find other one, and it would be A  B or, reverse the direction of vector B 



#6
Aug2807, 10:07 PM

HW Helper
P: 4,125

another idea... draw both vectors originating from the same point... what is the vector joining the arrow ends of B and A? 



#7
Aug2807, 10:08 PM

P: 27

Yes, I know what you are referring to about the B pertaining to its opposite direction, but the problem is I only know how to find the resultant magnitude for A + B and don't know how to find it for A  B because it's different since it's only two vectors and not more. 



#8
Aug2807, 10:10 PM

P: 27





#9
Aug2807, 10:11 PM

HW Helper
P: 4,125





#10
Aug2807, 10:13 PM

HW Helper
P: 4,125





#11
Aug2807, 10:14 PM

P: 27





#12
Aug2807, 10:15 PM

P: 27





#13
Aug2807, 10:20 PM

HW Helper
P: 4,125

if you calculate the x component (call it x) and y component (call it y) of A+B... then you can use the pythagorean theorem to calculate the magnitude... so maginitude = [tex]\sqrt{x^2 + y^2}[/tex] but this is not equal to [tex]\sqrt{A^2 + B^2}[/tex] ie: A and B are not the x and y components of A+B... 



#14
Aug2807, 10:22 PM

P: 27





#15
Aug2807, 10:23 PM

HW Helper
P: 4,125

Have you studied the law of cosines and the law of sines for triangles (nonright triangles)?
EDIT: You can also calculate the xcomponent of AB, and the ycomponent of AB... then use pythogrean theorem. Both approaches are good... it's up to you... 



#16
Aug2807, 10:28 PM

P: 27





#17
Aug2807, 10:32 PM

P: 27





#18
Aug2807, 10:34 PM

HW Helper
P: 4,125

you've got the triangle made up of A, B, and AB... You already know A, B and the angle between these two... So you've got a triangle where you know two sides, and the angle between the two sides... you want the third side... do you see how to use the cosine rule here to calculate the third side? 


Register to reply 
Related Discussions  
What does this position require/mean?  Academic Guidance  0  
Require Assistance.  Introductory Physics Homework  4  
Require Much Needed Help.  Introductory Physics Homework  3  
Require help  Differential Equations  4  
Does EPR require entanglement?  General Physics  8 