Potential Due to collection of point charges

AI Thread Summary
The discussion centers on calculating the electric potential at x=0 due to an infinite series of point charges placed along the x-axis. The participants clarify that the potential can be expressed as V(0) = (Q/(4πε₀)) * Σ(1/(2^i a)), where Q is the charge and a is the distance. One user expresses frustration with their calculations, initially arriving at an incorrect numerical value. Others encourage evaluating the sum rather than providing direct answers, emphasizing the importance of understanding the underlying concepts. The conversation highlights the significance of correctly applying the formula for electric potential in the context of an infinite series of point charges.
GingerBread27
Messages
108
Reaction score
0
As shown below, an infinite number of point positive charges of 8.0 C are placed on the x-axis at x=a, 2a, 4a, 8a, ... with a=18 cm. Find the electric potential (in V) at the point x=0.

0---a----2a---4a-----8a-------

Ok so I'm using the equation V=1/(4piEpsilon)Sigma(q/r). and it's not working! I don't understand what I'm doing wrong it should be pretty easy. Please help. I'm using 8 Coulombs as my q and r is my changing variable. I'm getting 88.88 and it's not working.
 
Physics news on Phys.org
your method is fine... what is your answer in term of V,q,a...etc? (not the numerical value )
the following equation might help you
\sum_{x=0}^\infty \frac{1}{2^x} = 2
 
Last edited:
Your total potential is just the sum of all the separate potentials, so:
V(0) = \frac{Q}{4\pi\epsilon_0} \sum_{i=0}^\infty \frac{1}{2^i a}<br />

Now try to evaluate this sum and you'll get your answer :rolleyes:
 
Last edited:
-blah- stupid
 
sory, typo
please don't give out the answer...
leave some work for the OP to do
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Why Is Work Positive When Done Against the Electric Field?
Replies
22
Views
3K
Charge on a grounded conducting sphere in a uniform electric field, after ungrounding and movement
Replies
1
Views
1K
What is taken as datum level for the following absolute potentials?
Replies
2
Views
554
MIT OCW, 8.02 Electromagnetism: Potential for an Electric Dipole
Replies
1
Views
2K
A charge q approaching two stationary charges q1 and q2
Replies
7
Views
879
Point charge with very thin metal sheet along a spherical surface
Replies
21
Views
2K
Finding Constants: Potential and Field Analysis
Replies
5
Views
1K
Calculating the point where potential V = 0 (due to 2 charges)
Replies
2
Views
2K
Method of mirroring - metal plates
Replies
11
Views
2K
What is the magnitude of the field at point R?
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top