Webassign even my ta's didn't know what to do ? and im in intro to physics

Rearrange the second equation to solve for L, then plug into the first equation to solve for A. Once you have A, you can use the equation for the area of a circle (A=\pi r^2) to solve for the radius. Then use that radius to find the diameter. In summary, to find the diameter of a 33 ohm resistor made from a coil of Cu wire with a mass of 12g, use the equations R=\rho \frac{L}{A} and m=dAL to find the length and cross-sectional area of the wire, and then use A=\pi r^2 and the calculated area to find the radius and diameter.
  • #1
phys-lexic
29
0
webassign even my ta's didn't know what to do... ?... and I am in intro to physics

Homework Statement


A 33 ohm resistor is made from a coil of Cu wire whose total mass is 12g. (a)What is the diameter of the wire and (b) how long is it ? ( give you answer in m)



Homework Equations


one equation my ta tried to use was (R) = (resistivity) x (L/A)


The Attempt at a Solution


no idea... we can't figure out where to go because the equation has both length and radius (in the equation for A of the cross section of the wire) as variables... this is the only question left on my webassign and i have 30 mins left... please help
 
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  • #2


There is a mass in the problem. There's a second equation that says mass=density*volume=density*length*area.
 
  • #3


Two equations, two unknowns. Solve:

[tex]R=\rho \frac{L}{A}[/tex] and [tex]m=dV=dAL[/tex] where d is density and rho is resistivity
 

FAQ: Webassign even my ta's didn't know what to do ? and im in intro to physics

1. How do I access my Webassign account?

To access your Webassign account, you will need to log in with your unique username and password that was provided by your instructor. If you do not have this information, you can contact your instructor or the Webassign support team for assistance.

2. I am having trouble understanding the questions on Webassign. What should I do?

If you are struggling with understanding the questions on Webassign, it is important to first review the material covered in your Intro to Physics class. You can also reach out to your instructor or TA for clarification or attend any available tutoring sessions. Additionally, Webassign provides a help feature that includes explanations and examples for each question.

3. Can I use a calculator on Webassign?

Yes, you can use a calculator on Webassign. However, it is important to note that some questions may require you to show your work and not just provide the final answer. In these cases, make sure to use a calculator that allows you to show your steps.

4. I am receiving an error message when submitting my answer on Webassign. What does it mean?

Error messages on Webassign can occur for a variety of reasons, such as incorrect formatting, using the wrong units, or entering the wrong answer. Make sure to carefully read the question and follow any specific instructions provided. If you are still having trouble, you can reach out to your instructor or TA for assistance.

5. Can I work on Webassign with a group or with my classmates?

Webassign is designed for individual use and is not intended for group work. However, you can discuss the material with your classmates and work together to understand the concepts. It is important to note that each student should still submit their own answers and show their own work.

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