Scalar potential in EM and Newton's Law

  • Thread starter luxiaolei
  • Start date
  • #1
75
0

Main Question or Discussion Point

Hi,all, problem is:

in Electromagnetism, we introduced a scalar potential psi, such that:

E = - grad Psi

and In newton's law, there is also a scar potential U, such that:

F= -grad U

My question is, one is the gradient of a scalar field give a field and a force???!!

Can anyone help me with understanding this? That would be great, and many thanks in advance!
 

Answers and Replies

  • #2
29,277
5,594
The field is just a force scaled by charge. It is the same relationship as e.g. the gravitational field and weight.
 
  • #3
75
0
The field is just a force scaled by charge. It is the same relationship as e.g. the gravitational field and weight.
@DaleSpam; thanks for replay. I am very interested in your answer, however, I am not quite understood it. Would you explain it more? thanks

Can I say,

Electric force = -grad psi = E

or

Gravitation field = -grad U = F

if they are the same.
 
  • #4
29,277
5,594
Yes. For example, if U = kCc/r then you get the electric force, if psi = kC/r then you get the electric field. Similarly, if U = GMm/r you get the gravitational force, if psi = GM/r then you get the gravitational field.
 
  • #5
75
0
Yes. For example, if U = kCc/r then you get the electric force, if psi = kC/r then you get the electric field. Similarly, if U = GMm/r you get the gravitational force, if psi = GM/r then you get the gravitational field.
Thanks a lot!! Cleared my mind!
 

Related Threads on Scalar potential in EM and Newton's Law

Replies
5
Views
1K
Replies
16
Views
9K
Replies
0
Views
3K
Replies
1
Views
976
  • Last Post
Replies
1
Views
527
  • Last Post
Replies
4
Views
6K
Replies
4
Views
728
  • Last Post
3
Replies
61
Views
10K
  • Last Post
Replies
24
Views
29K
Top