Did I find an error in webassign?

  • Thread starter FCguy
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In summary, the conversation discusses a potential error found in a WebAssign problem and the correct solution to the problem. The participants also mention the tolerance and programming involved in creating these types of problems. One participant suggests watching videos on YouTube for a better understanding of physics.
  • #1
FCguy
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I think I found an error in a webassign problem. What do you think?

bad question.png
 
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  • #2
FCguy said:
I think I found an error in a webassign problem. What do you think?

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WebAssign is right (at least in this case).
 
  • #3
In that term, you should be using 0.05m (12.0 N) sin(60) or cos(30) which gives an answer of -3.85.
-3.77 is within 3% of the correct answer. So now you know your teacher set the tolerance to at least 3%. :)
 
  • #4
tony873004 said:
In that term, you should be using 0.05m (12.0 N) sin(60) or cos(30) which gives an answer of -3.85.
-3.77 is within 3% of the correct answer. So now you know your teacher set the tolerance to at least 3%. :)

I should elaborate that I answered with -3.85 and it rejected that answer. Also, our professor informed us that tolerance is 1%. Finally I have a photo of the "master it" help portion in which webassign shows the calculation without the trig.

bad master it.png
 
  • #5
If it rejected -3.85, then this is a Webassign bug. I teach Physics. I wrote my own "webassign-like" software. I set the tolerance to 1%. It still requires that I do the problems properly. Sometimes I don't. I make the same careless mistakes my students make. In that case, the system accepts wrong answers as right, and marks right answers as wrong. I give EC to the first student that finds a bug (cheaper than hiring an editor!) I imagine the Webassign authors have the same issues. Email them. They'll be happy to get free proofreading.

Is this problem directly from Webassign, or did your teacher create it? Webassign allows instructors to create their own problems. They have to spell out the solutions in Perl programming language. Maybe your teacher made a mistake
 
  • #6
tony873004 said:
Is this problem directly from Webassign, or did your teacher create it? Webassign allows instructors to create their own problems. They have to spell out the solutions in Perl programming language. Maybe your teacher made a mistake

I believe these problems are created by webassign, not by my professor. Thanks for the confirm on the answer. I've emailed webassign. Teach on prof! I'm curious as to what level of education you instruct. I never took physics in high school but boy would it have helped now.
 
  • #7
I had the same instinct as Sammy, namely that the 12N force was tangent and the dotted line was a red herring.

The answer depends on where the force is being applied, which is a bit ambiguous from the picture.
 
  • #8
I teach high school AP C Mechanics, similar to your first engineering-level Physics class in college.
It comes at you quick if you've never learned it "conceptually", and you're learning it with algebra, trig and calculus the first time you've seen it.
Go to youtube and find as many Paul Hewitt videos as you can. He explains Physics in a way that a 2nd grader could get it. He never uses Calc or trig, and rarely uses any numbers greater than 10. And he's very entertaining.
 
  • #9
Nathanael said:
I had the same instinct as Sammy, namely that the 12N force was tangent and the dotted line was a red herring.

The answer depends on where the force is being applied, which is a bit ambiguous from the picture.
Actually, you're right! The pull is tangent. 30 degrees doesn't have anything to do with the problem. The angle is 0 from the tangent I fell for the trap. -3.77 is correct. I didn't catch the red herring! Nothing ambiguous here. Like I said a few posts ago, I often make the same mistakes as my students.
 
  • #10
Nathanael said:
I had the same instinct as Sammy, namely that the 12N force was tangent and the dotted line was a red herring.

The answer depends on where the force is being applied, which is a bit ambiguous from the picture.

I agree with your observation in retrospect but I still believe that this particular red herring was incorporated in such a way that they actually changed the problem. The 12N arm certainly appears to be crossing the circumference of the inner circle. They should have used something like 80 degrees to clearly show they didn't mean for the force to be passing through the circle.
 
  • #11
They probably were thinking of a yo-yo where the 12N pulls was pulling on the spindle
 

FAQ: Did I find an error in webassign?

1. What should I do if I think I found an error in Webassign?

If you believe you have found an error in Webassign, you can report it to the Webassign support team. They will review your report and make any necessary corrections to the system.

2. How do I know if the error I found is actually an error?

If you are unsure if the issue you encountered is an error or not, you can check the Webassign forums to see if others have experienced the same problem. You can also contact the Webassign support team for clarification.

3. Will reporting an error in Webassign affect my grade?

No, reporting an error in Webassign will not affect your grade. The support team will review and correct any errors in the system, ensuring that all students have a fair and accurate assessment.

4. How long does it take for an error in Webassign to be fixed?

The time it takes to fix an error in Webassign can vary depending on the complexity of the issue. However, the support team strives to resolve all reported errors as quickly as possible.

5. Can I get extra credit for finding an error in Webassign?

While finding an error in Webassign shows your attention to detail and critical thinking skills, it is not guaranteed to earn you extra credit. However, your instructor may choose to give extra credit for reporting errors, so it is always worth mentioning to them.

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