How is Work Calculated in an Electric Field?

AI Thread Summary
Work done on an electron in an electric field is calculated using the formula W = eV, where W represents work, e is the charge of the electron, and V is the potential difference. It is clarified that V is constant during the movement of the charge, as it refers to the potential difference the charge moves through rather than its position. The confusion arises from the assumption that V changes as the charge moves, but the correct interpretation is that the work done is based on the potential difference. The discussion highlights the importance of understanding the distinction between potential at a point and potential difference during movement. This understanding is crucial for accurately calculating work in electric fields.
jsmith613
Messages
609
Reaction score
0

Homework Statement



attachment.php?attachmentid=144240&d=1335453216.png


Homework Equations


The Attempt at a Solution



now I know this has something to do with energy done on electron and KE.

apparently work done on electron is:
W = eV

BUT surely this implies V is constant. as the charge moves, will not V change?
hence it should be
W = 0.5*eV?
 
Physics news on Phys.org
found it
my book says V is the p.d that charges MOVE THROUGH not are in :)
 

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 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
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
Work done on dipole and potential energy in uniform electric field
Replies
4
Views
3K
Work Done on A Proton in an Electric Field
Replies
1
Views
3K
Work Done by an Induced Electric Field
Replies
2
Views
2K
Work done to insert a point charge 𝑞 at the center of a conducting sphere
Replies
12
Views
1K
Understanding the energy of a dipole in a uniform electric field
Replies
2
Views
2K
Capacitors, equipotentials, and electric fields
Replies
5
Views
886
Confused about direction of electric field
Replies
7
Views
3K
Why are the electrostatic field lines normal to a charged conductor?
Replies
10
Views
1K
Calculating work done by an Electric field on a positive charge
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top