Determining Work Based on a Charge and Particle

AI Thread Summary
The potential at a point is -4.5E3 V, and the work done to bring a 0.94 C charge from infinity to that point is calculated using the formula W = V * Q. The calculation performed was -4500 V * 0.94 C, resulting in -4230 J. The units confirm that the result is in Joules, validating the calculation. The student expressed concern about the simplicity of the problem, given their instructor's tendency to present trick questions.
rabiddogma
Messages
3
Reaction score
0

Homework Statement


The potential at a point is -4.5E3 V. How much work, in J, is done to bring a 0.94 C charge from infinity to the point?

Homework Equations


1V = 1 J/C

The Attempt at a Solution


Well I know that 1 V = 1 J/C so I did -4500V*0.94C = -4230J but I wasn't sure if this was right.
 
Last edited:
Physics news on Phys.org
rabiddogma said:

Homework Statement


The potential at a point is -4.5E3 V. How much work, in J, is done to bring a 0.94 C charge from infinity to the point?


Homework Equations


1V = 1 J/C


The Attempt at a Solution


Well I know that 1 V = 1 J/C so I did -4500V/0.94C = -4230J but I wasn't sure if this was right.

Check how the units multiply out in your calculation. Do you get Joules?
 
gneill said:
Check how the units multiply out in your calculation. Do you get Joules?

Ah my bad, that was a typo, what I did was -4500V*0.94C. Which does come out to J but I wasn't sure if that gave the proper answer.
 
rabiddogma said:
Ah my bad, that was a typo, what I did was -4500V*0.94C. Which does come out to J but I wasn't sure if that gave the proper answer.

Alright. In that case the result looks fine :smile:
 
gneill said:
Alright. In that case the result looks fine :smile:

Alright, thanks, I just wasn't sure because my instructor has a tendency of giving us trick problems and that just seemed too easy.
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Uniform distribution of charge and work needed
Replies
12
Views
3K
Work done to insert a point charge 𝑞 at the center of a conducting sphere
Replies
12
Views
1K
Speed of two charged particles repelling each other
Replies
7
Views
3K
What is the induced magnetic force on this closed current loop?
Replies
12
Views
2K
Kinetic and potential energy of a particle attracted by charged sphere
Replies
6
Views
2K
Find the amount of work to move a particle from point A to B
Replies
4
Views
2K
MIT OCW, 8.02 Electromagnetism: Potential for an Electric Dipole
Replies
1
Views
2K
Change in potential energy of the particle
Replies
1
Views
2K
Work done in assembling a system of charges
Replies
1
Views
3K
Work to bring a charge to the center of two quarter circles
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top