Solving Vector A: What am I Doing Wrong?

  • Thread starter QuarkCharmer
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In summary, the student is frustrated because they think they are getting closer to a solution but each answer they submit is incorrect. They are down to their last shot and are frustrated because they think they know the answer.
  • #1
QuarkCharmer
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Homework Statement


e8vds9.jpg


Homework Equations



The Attempt at a Solution



So, given these two components of the vector A, to find the angle the vector makes with the X axis I simply did the following:

5le6a0.jpg


So theta is -71.1 with significant figures.

and that's not the expected answer either?
What am I doing wrong?

Do they really want the angle "measured counterclockwise from that axis" meaning:
360-71.1 ?
 
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  • #2
Do they really want the angle "measured counterclockwise from that axis" meaning:
360-71.1

-71.1 looks right, so does 360-71.1. You have 4 shots left, why not give it a try?
 
  • #3
lewando said:
-71.1 looks right, so does 360-71.1. You have 4 shots left, why not give it a try?

I think each "shot" takes off some points. Because the instructions says that it wants the angle counterclockwise from the +x axis, (which I assume is the positive side of the x axis) then I am thinking that the latter answer is correct.

This is silly, considering all the talk about "bowtie" angles and whatnot by my actual professor in class.
 
  • #4
If the automated answer checking machine cannot deal with negative angles, that is a limitation of the machine, not you. If, as a result of this machine limitation, you have wasted a shot by entering a perfectly valid -71.1 degrees (with respect to positive angles being measured in the CCW direction from the +x axis) then you should insist that your professor return those couple of points only if you are between grades and think that a couple of points will matter. Otherwise, don't worry about it and fire away with the positive angle answer.

P.S. How do you know the machine is looking for degrees, not radians? What are the ground rules for submitting angle results?
 
  • #5
lewando said:
P.S. How do you know the machine is looking for degrees, not radians? What are the ground rules for submitting angle results?

There is a little degree symbol next to the answer field.

I'm down to my last shot at this question, this is frustrating because I know that every single one of my answers were correct.
 

Related to Solving Vector A: What am I Doing Wrong?

1. Why am I getting an error when trying to solve Vector A?

There could be a few reasons for this. First, make sure you are using the correct formula for solving Vector A. Double check your calculations to ensure there are no mistakes. Also, check for any missing or incorrect values in your problem's given information. Finally, make sure you are using the correct units for your vectors.

2. How do I know if my solution for Vector A is correct?

You can check your solution by using the Pythagorean theorem to calculate the magnitude of your vector. If your solution matches the magnitude you calculated, then it is likely correct. You can also use a vector calculator to check your solution.

3. Can I solve Vector A without using the Pythagorean theorem?

Yes, there are other methods for solving Vector A such as using trigonometric functions or the law of cosines. However, the Pythagorean theorem is the most common and straightforward method for solving Vector A.

4. Can I solve Vector A if I only have the magnitude and direction?

Yes, you can use the magnitude and direction of a vector to determine its components and solve for Vector A. You can use trigonometric functions to find the components and then use the Pythagorean theorem to solve for the vector's magnitude.

5. What should I do if I am still having trouble solving Vector A?

If you are having trouble solving Vector A, try reviewing the concept of vector addition and subtraction. Make sure you understand the properties and formulas involved. You can also consult with a teacher or tutor for further assistance.

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