Vector 2B - Vector A (graphical method)

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Homework Help Overview

The problem involves vector operations, specifically using a graphical method to find the resultant of the expression 2B - A, where Vector A is 4.00 units at an angle of 40 degrees below the x-axis and Vector B is 3.00 units at an angle of 25 degrees below the negative x-axis. Participants are tasked with determining the magnitude and direction of the resultant vector.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the graphical method of vector addition and subtraction, questioning whether the provided lengths represent the x-components of the vectors. There is confusion regarding the doubling of Vector B and how to accurately represent the vectors graphically. Some participants express uncertainty about the steps taken and the interpretation of the problem statement.

Discussion Status

The discussion is ongoing, with participants sharing their attempts and expressing confusion over the graphical representation and the calculations involved. Some guidance has been offered regarding the process of vector subtraction and the need to consider the direction of the vectors.

Contextual Notes

Participants are working under the constraint of using only a ruler and protractor for their graphical method. There is a noted lack of clarity in the problem statement that is contributing to the confusion about the operations required.

s31t8n8
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Homework Statement



Vector A is 4.00 units and 40* below x-axis. Vector B is 3.00 units and 25* below -x-axis. Use the graphical method (only ruler and protractor) to find Vector 2B - Vector A. I have to find the magnitude and direction.

When I did it I got 8.5 and East, but I'm not sure if I did it right. When they say 4.00 and 3.00 units, is that the ax component of the vector? That's the way I did it. I drew out the vector then measured 3 and 4 units on the ax comp. of both vectors, then measured from that point down to the vector and got the ay component. Then I just solved for the magnitude.

thanks
 
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s31t8n8 said:

Homework Statement



Vector A is 4.00 units and 40* below x-axis. Vector B is 3.00 units and 25* below -x-axis. Use the graphical method (only ruler and protractor) to find Vector 2B - Vector A. I have to find the magnitude and direction.

When I did it I got 8.5 and East, but I'm not sure if I did it right. When they say 4.00 and 3.00 units, is that the ax component of the vector? That's the way I did it. I drew out the vector then measured 3 and 4 units on the ax comp. of both vectors, then measured from that point down to the vector and got the ay component. Then I just solved for the magnitude.

thanks

The vector length is 4 at an angle of 40 degrees down below positive X axis and the other vector is 3 long pointing down from the negative x-axis. (The other direction of x)

But they say 2*B which makes that vector 6 long.
 
LowlyPion said:
The vector length is 4 at an angle of 40 degrees down below positive X axis and the other vector is 3 long pointing down from the negative x-axis. (The other direction of x)

But they say 2*B which makes that vector 6 long.

ok i just redrew it and now I am lost. I am getting confused about what theyre asking
 
s31t8n8 said:
ok i just redrew it and now I am lost. I am getting confused about what theyre asking

You've drawn the two vectors - doubling B?

Then reverse Vector A - same length - opposite direction.

They say 2*B - A right. This is vector subtraction. But you do that by "adding" the negative of the Vector A.

Now add these two vectors together.
 
ok i did it again and I am sure i got it wrong again but i got
2*B-A= -.8i-.6j
magnitude = 1
 

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