Static Electricity and particles

AI Thread Summary
The discussion revolves around calculating the net force on three charged particles: +70 µC, +48 µC, and -80 µC, arranged in a line with specific distances. The user initially applies the formula F=kq1q2/d² but struggles with the correct application, particularly in considering the signs of the forces and their vector nature. They are advised to draw a diagram, analyze one charge at a time, and carefully account for the distances and directions of the forces. Despite performing calculations, the user receives feedback that their final answer is incorrect, indicating a misunderstanding in the superposition of forces. The thread emphasizes the importance of correctly applying vector addition and considering the effects of charge signs on force direction.
me_and_you
Messages
6
Reaction score
0

Homework Statement



Particles of charge +70, +48, and -80 \muC are placed in a line, in the previous order. The center one is .35 m from each of the others. Calculate the net force on each charge due to the other two.

Homework Equations



F=kq1q2/ d2


The Attempt at a Solution



I found the force between each but according to my teacher I am not doing this correctly could someone please tell me how i should go about doing this problem.
 
Physics news on Phys.org
Draw a diagram. Consider one charge at a time.

The ones on the end will be .35 and .7 distant from the other 2 respectively.

Be careful with the signs. Be careful with the units.

Be careful that you have taken care to note the direction of the force in each equation. (+,-) attracts and same sign repels.

Since forces are vectors then you must take that into account when you add them by superposition.
 
I thought that's what I was doing but after trying again i got the same wrong answer, I'm so confused about wht i should do with this problem!
 
Show your calculation then for the middle charge.
 
LowlyPion said:
Show your calculation then for the middle charge.

F1= (9x109)(70 x 10-6)(48x10-6)/ .352

this equals: 246.86

F3= (9x109)(-80 x 10-6)(48x10-6)/ .352


this equals: -282.1

Then i did
(246.862)+ (-282.12)= Q2

Q= 374C

but according to my teacher this is wrong... can you tell me what it is that I am doing wrong?
 

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

External forces required to move an electric dipole quasi-statically
Replies
14
Views
1K
Static equilibrium | Uniform sphere on incline | Determining friction
Replies
43
Views
2K
Dipole placed in a uniform electric field
Replies
11
Views
3K
Why is electric field at the center of a charged disk not zero?
Replies
4
Views
3K
Find net velocity of charged particle in electric field (symbols only)
Replies
14
Views
3K
Question about charged particle in an electric field
Replies
5
Views
2K
Induction confusion for induced charge inside a metal conductor
Replies
23
Views
903
Electric field at a point within a charged circular ring
2
Replies
68
Views
7K
Electromagnetic force on particles forming a square
Replies
5
Views
2K
Two spring-coupled masses in an electric field (one of the masses is charged)
Replies
1
Views
862

Hot Threads

Recent Insights

Back
Top