# Need some help with this Physics problem

In summary, the conversation discusses a problem involving magnetic and electric fields, tensions in strings, and components. The weight of the wires and the forces involved are considered, and various equations are used to solve the problem. Ultimately, the correct answer is found through careful calculations.
Hi,
I have a problem here that I'm having trouble with, I attempted to do it by using equations dealing with magnetic fields and electric fields, but then i had to consider the tensions of the strings and the components and became lost. Can anyone help me?

Here is the problem:
http://img.villagephotos.com/p/2004-9/824584/stupid5.jpg

Thanks again

Consider the weight of some length of the wires. The tension in the string has to support the weight and pull the wires together. If T is the tension, the weight is T cos (7.5) and the horizontal force is T sin (7.5) The horizontal force from the tension is equal to the force of repulsion due to the currents.

ok, I did what you said and got the current as 91.8A, but is this right? I found the horizontal force to be 1.29 and the length between the wires to be .0259 meters, then i used the equation, F/L= (permeability of freespace)(I^2)/ 2(pi)r, and I took the force and multipled it by the .050 kg/m then solved for the I in the equation. Is this right? or is there something I;m doing wrong.

Thanks for the help

Chances are pretty good when you do a multiple choice question and get exactly one of the answers, you have done it right. You have the right equation for F/L. I don't know what your units are for a horizontal force of 1.29. Do you mean force per unit length in N/m? Something else? I don't see 1.29 coming out of the numbers. The horizontal force on each wire is about .132 times the weight, with the tension in the string being about 1.00863 times the weight. Check your calculations, and then believe them.

## 1. What steps should I follow to solve this physics problem?

To solve a physics problem, you should first carefully read and understand the given information and the question. Then, identify the relevant concepts and equations that apply to the problem. Next, plug in the known values into the appropriate equations and solve for the unknown variable. Finally, double-check your answer and make sure it is reasonable.

## 2. How do I know which formula to use for a specific physics problem?

The formula to use for a physics problem depends on the given information and the unknown variable you are trying to solve for. You should carefully read the question and identify the relevant concepts and equations. If you are unsure which formula to use, you can consult your textbook or ask your teacher for guidance.

## 3. What should I do if I am stuck on a physics problem?

If you are stuck on a physics problem, take a break and come back to it later with a fresh perspective. You can also try breaking the problem down into smaller parts or working through similar practice problems to gain a better understanding. Don't be afraid to seek help from your teacher or classmates if needed.

## 4. Can I use a calculator to solve a physics problem?

Yes, you can use a calculator to solve a physics problem. However, make sure you are using the correct units and rounding to the appropriate number of significant figures to ensure an accurate answer. Some problems may also require you to show your work by hand, so be sure to read the instructions carefully.

## 5. How can I check if my answer to a physics problem is correct?

To check if your answer to a physics problem is correct, you can use online calculators or ask your teacher to verify your solution. You can also double-check your calculations and units to make sure they are accurate. If your answer seems unreasonable, go back and review your steps to see if you made a mistake.

• Introductory Physics Homework Help
Replies
2
Views
374
• Introductory Physics Homework Help
Replies
3
Views
535
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
3
Views
460
• Introductory Physics Homework Help
Replies
9
Views
2K
• Introductory Physics Homework Help
Replies
13
Views
680
• Introductory Physics Homework Help
Replies
1
Views
807
• Introductory Physics Homework Help
Replies
1
Views
992
• Introductory Physics Homework Help
Replies
7
Views
311
• Introductory Physics Homework Help
Replies
24
Views
2K