Can a tiny magnet push away a larger one?

  • Thread starter Thread starter acistephanie
  • Start date Start date
  • Tags Tags
    Electromagnetic
AI Thread Summary
A tiny magnet cannot push away a larger magnet due to Newton's third law, which states that forces are equal and opposite. Even if one magnet is significantly larger, the smaller magnet will exert an equal force back. This principle means that if both magnets are attached to a boat, the boat will not move. The discussion highlights the impossibility of such scenarios, referencing the fictional story of Baron Munchausen as an analogy. Ultimately, the forces involved in magnetism adhere to established physical laws, making the idea unfeasible.
acistephanie
Messages
1
Reaction score
0
Thanks
 
Last edited:
Physics news on Phys.org
No, it won't work. The forces will be equal, and opposite.

Creative idea however.
 
Newton's third law tells you the forces will be equal. If both magnets are attached to the boat it won't go anywhere.
 
How was the story of Baron Munchausen guy lift himself up by his ponytail from the quicksand. Does not work :)
 
acistephanie said:
I don't understand. If you have a really big magnet and put it next to a really tiny one. Wont the tiny one get pushed away. Why would forces be equal? Couldn't I just amp up one of them?
kanato said:
Newton's third law tells you the forces will be equal. If both magnets are attached to the boat it won't go anywhere.
Yup, Newton's third law is the key concept here. As hard as it may be to believe, the smaller magnet pushes back on the larger one with an equal amount of force.

If not for the validity of Newton's third law , stuff like this would be possible (which it isn't):
vlado_skopsko said:
How was the story of Baron Munchausen guy lift himself up by his ponytail from the quicksand. Does not work :)
 

Thread 'Maxwell stress tensor'

This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
View full post »
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'

Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'

Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
View full post »

Similar threads

B Changing magnetic polarity of an electromagnet
Replies
10
Views
2K
A Magnetization and magnet poles
Replies
10
Views
2K
B Understanding magnetic flux change during the falling of magnet
Replies
1
Views
1K
B What is the difference between B and H?
Replies
14
Views
2K
B Is the Kink in the Electromagnetic Wave Responsible for Delayed Motion?
Replies
8
Views
2K
I Can Electromagnetic Levitation Make an Entire Apparatus Go Skyward?
Replies
3
Views
1K
I Permanent Magnetic Dipole in an electromagnetic field
Replies
2
Views
2K
I What causes skin effect in AC currents?
Replies
2
Views
1K
I Two ways of constructing electromagnetism, which is correct?
Replies
7
Views
1K
I The vector math of relative motion of wire-loop & bar magnet
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top