MasteringPhysics.com problem (Electric Field)

In summary: Glad I could help. In summary, the net force exerted by the two point charges on the third charge is approximately -1.48 * 10^13 N. This is a large force due to the strong electric fields created by the two point charges.
  • #1
adam32386
2
0
Two point charges are located on the x axis: one charge, q_1 = -19.5 nC, is located at -1.660 m ; the second charge, q_2 = 38.0 nC, is at the origin (x=0).


What is the net force exerted by these two charges on a third charge q_3 = 48.5 nC placed between q_1 and q_2 at x_3 = -1.210 m?

Note that your answer may be positive or negative, depending on the direction of the force.

Use 8.85×10−12 C^2/(N \cdot m^2) for the permittivity of free space.


I have no idea how to do this. any help?
thank you
 
Physics news on Phys.org
  • #2
Use superposition.
 
  • #3
You must show some work or thought on the problem to get help here. We do not do homework problems for people, we help people do their own homework problems.

So, give me some thought on this problem. Can you find the force from one of the charges? What about the force from the other one then? How do you go about adding the two quantities?
 
  • #4
Hay, I'm stuck on the same problem but have some working. :P

e = 8.854 x 10^-12

Consider two point charges located on the x axis: one charge, q_1 = -11.5 nC, is located at x_1 = -1.665 m; the second charge, q_2 = 38.5 nC, is at the origin (x=0.0000). What is the net force exerted by these two charges on a third charge q_3 = 53.5 nC placed between q_1 and q_2 at x_3 = -1.215 m?

MasteringPhysics is saying its wrong. :(
http://files.trozza.com/Uni/2010/Physics%201a/Electromagnatism.jpg

I only have one attempt left and I'm not sure what I could be doing wrong.. Perhaps it should be positive?

Kind Regards,
Troz
 
  • #5
Trozza said:
Hay, I'm stuck on the same problem but have some working. :P

e = 8.854 x 10^-12

Consider two point charges located on the x axis: one charge, q_1 = -11.5 nC, is located at x_1 = -1.665 m; the second charge, q_2 = 38.5 nC, is at the origin (x=0.0000). What is the net force exerted by these two charges on a third charge q_3 = 53.5 nC placed between q_1 and q_2 at x_3 = -1.215 m?

MasteringPhysics is saying its wrong. :(
http://files.trozza.com/Uni/2010/Physics%201a/Electromagnatism.jpg

I only have one attempt left and I'm not sure what I could be doing wrong.. Perhaps it should be positive?

Kind Regards,
Troz

You missed a negative on F2.
 
  • #6
Thanks for the prompt reply.

So I should be getting something around (-)1.48 *10^13?

The 10^13 part seems very large and wrong to me. Its something like 14.7 Tera Newtons... Awfully large force..
 
  • #7
Trozza said:
Thanks for the prompt reply.

So I should be getting something around (-)1.48 *10^13?

The 10^13 part seems very large and wrong to me. Its something like 14.7 Tera Newtons... Awfully large force..

Charge is given in nano-coloumbs (nC) not coulumbs.
 
  • #8
zachzach said:
Charge is given in nano-coloumbs (nC) not coulumbs.

Thanks I missed it. :P So I re-did the calculations based on your help, and I think it produces a much more sensible answer. Does this look correct? The magnitude is at least looking better :P

http://files.trozza.com/Uni/2010/Physics%201a/ElectromagnatismUpdate.jpg
 
  • #9
Trozza said:
Thanks I missed it. :P So I re-did the calculations based on your help, and I think it produces a much more sensible answer. Does this look correct? The magnitude is at least looking better :P

http://files.trozza.com/Uni/2010/Physics%201a/ElectromagnatismUpdate.jpg

Draw the electric field lines to see which way they point on the x-axis. They both add but both are in the negative x direction.
 
  • #10
zachzach said:
Trozza said:
Draw the electric field lines to see which way they point on the x-axis. They both add but both are in the negative x direction.

Sweet, I think I have it now..

http://files.trozza.com/Uni/2010/Physics%201a/ElectromagnatismUpdate2.jpg
But minus... I didn't write that bit in before scanning.
 
  • #11
Right.
 
  • #12
Sweet, thanks Heaps Zach, just typed it into mastering physics and it said correct.
 
  • #13
Sweet, no problem.
 

Related to MasteringPhysics.com problem (Electric Field)

1. What is MasteringPhysics.com?

MasteringPhysics.com is an online learning platform designed to help students improve their understanding and mastery of physics concepts. It provides interactive problem sets, tutorials, and other resources to help students practice and learn physics concepts.

2. How do I access MasteringPhysics.com?

To access MasteringPhysics.com, you will need to have an access code provided by your instructor or purchase one online. Once you have the access code, you can create an account and log in to the platform.

3. What is an Electric Field?

An electric field is a region in space where an electric charge experiences a force. It is represented by vector arrows pointing in the direction of the force a positive charge would experience if placed in that field. The strength of the electric field is measured in units of Newtons per Coulomb (N/C).

4. How do I solve a problem on MasteringPhysics.com related to Electric Fields?

To solve a problem on MasteringPhysics.com related to electric fields, you will first need to understand the concept being tested. Then, you can use the tools provided on the platform, such as interactive simulations and equations, to manipulate and analyze the given scenario. Make sure to pay attention to units and use proper notation when entering your answers.

5. What if I am having trouble with a problem on MasteringPhysics.com?

If you are having trouble with a problem on MasteringPhysics.com, there are several resources available to help you. You can use the "Help Me Solve This" button to receive step-by-step guidance, watch tutorial videos, or consult with your instructor or peers for assistance. It is important to keep trying and use the available resources to improve your understanding and skills.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
26
Views
837
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
381
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
988
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
Back
Top