How Does Charge Movement Affect Electric Field Perception in Different Frames?

  • Thread starter Thread starter vin300
  • Start date Start date
  • Tags Tags
    Field Frames
AI Thread Summary
The discussion explores how the movement of charges affects electric field perception in different reference frames. Charge 3, moving in a magnetic field, perceives an electric field in the positive z-direction, while charges 1 and 2, at rest in the initial frame, experience an electric field in the negative z-direction. This leads to a contradiction where charge 1 is accelerated in the negative z-direction, while charge 2 is forced in the positive z-direction, despite both being at rest initially. The induced electric fields are calculated using the Lorentz factor, revealing that the forces acting on the charges depend on their respective charges and velocities. The scenario highlights the complexities of charge interactions and electric field perception across different frames of reference.
vin300
Messages
602
Reaction score
4
Charge 1=+e
Charge 2=-e
Charge 3=+e




If chg3 moves along the positive x in a magnetic field directed in +ve y, it sees an electric field in the +ve z, then in this frame a chg 1 and 2 both in rest in the initial frame experience an electric field in the -ve z, with the positive charge accelerated in the -ve z and negative charge in the +ve z, but this is not possible because both + and - charges are at rest in the initial frame, so in chg 3's frame both must be accelerated in -ve z.
 
Physics news on Phys.org
If r is the lorentz factor,in chg1 and 2's comoving rest frames, for chg3's velocity v along + x and B along + y, the induced electric field is
E(z) =r[vxB/c]
In chg3's frame, charge 1 which is positive and charge 2 which is negative both move with a velocity -v, the induced electric field for each is
E'(z)=r[-vxB/c]
This is exactly equal and opposite to the former, but only charge 1 is accelerated in - z because the force also depends on charge. Charge2 is forced along +z, but this defies logic since in chg2's frame chg3 is accelerated along +z and in chg3's frame chg2 is accelerated along + z
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Back
Top