What is the Strength of the Electric Field?

Click For Summary
SUMMARY

The strength of the electric field can be calculated using the formula E1 = (k*p)/(r^2 + a^2)^(3/2). In this case, k is Coulomb's constant (9E9 N m²/C²), the charge is 3nC, and the distance r is 7.3cm. The dipole moment p is defined as p = 2aq, where a is half the length of the dipole. The correct calculation yields E1 = 906 N/C, indicating that the initial approach incorrectly used charge instead of the dipole moment.

PREREQUISITES
  • Understanding of Coulomb's law and its constant (k = 9E9 N m²/C²)
  • Knowledge of dipole moment calculation (p = 2aq)
  • Familiarity with electric field strength equations
  • Basic algebra for manipulating equations and solving for variables
NEXT STEPS
  • Study the derivation and applications of the dipole moment in electrostatics
  • Learn about electric field calculations for different charge configurations
  • Explore the significance of significant figures in scientific calculations
  • Investigate the relationship between electric field strength and distance from the charge
USEFUL FOR

Students studying electromagnetism, physics educators, and anyone involved in solving electrostatic problems or preparing for exams in physics.

littlejon
Messages
20
Reaction score
0

Homework Statement


Specify the strength of the electric field. Let r = 7.3cm .

Homework Equations


E1= (k*p)/(r^2+a^2)^3/2
Here k= constant used in Coulomb's law. a= half the length of dipole
p= dipole moment = charge x length of dipole. Charge = 3nC and length of dipole

The Attempt at a Solution


E1= (9E9)(3E-9)/(.146)^2+(.073)^2)^(3/2)= 6207

I got this wrong, but does anyone have any advice on how to solve this?
 

Attachments

  • physics problem.png
    physics problem.png
    2.8 KB · Views: 7,198
Last edited:
Physics news on Phys.org
littlejon said:

Homework Statement


Specify the strength of the electric field. Let r = 7.3cm .

Homework Equations


E1= (k*p)/(r^2+a^2)^3/2
Here k= constant used in Coulomb's law. a= half the length of dipole
p= dipole moment = charge x length of dipole. Charge = 3nC and length of dipole

The Attempt at a Solution


E1= (9E9)(3E-9)/(.146)^2+(.073)^2)^(3/2)= 6207

I got this wrong, but does anyone have any advice on how to solve this?
It appears that you used the amount of charge for p, rather than dipole moment.

## p=2aq ##
 
SammyS said:
It appears that you used the amount of charge for p, rather than dipole moment.

## p=2aq ##
Then ((9E9)(2*.073*3E-9))/((.146^2)+(.073)^2)^(3/2) = 906?
 
I'm surprised that a problem like this would have a be larger than r. Usually it's the other way around.

What is the complete problem you were given to solve? -- word for word.
 
SammyS said:
I'm surprised that a problem like this would have a be larger than r. Usually it's the other way around.

What is the complete problem you were given to solve? -- word for word.
What are the strength and direction of the electric field at the position indicated by the dot in the figure (Figure 1) ?
Specify the strength of the electric field. Let r = 7.3cm .
Express your answer using two significant figures.
Thats word for word.
 
littlejon said:
What are the strength and direction of the electric field at the position indicated by the dot in the figure (Figure 1) ?
Specify the strength of the electric field. Let r = 7.3cm .
Express your answer using two significant figures.
That's word for word.
In the figure, the charges have a separation, 2r . That is to say, a = r .

physics-problem-png.80347.png
 

Similar threads

Replies
4
Views
3K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
11
Views
1K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
7K
Replies
19
Views
4K