Slowing down a moving electric charge

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SUMMARY

To slow down a moving electric charge, an electrical force is required, as magnetic force acts perpendicular to the displacement and does not affect the charge's speed. The discussion emphasizes that while magnetic forces can alter the direction of a charge's velocity, they cannot reduce its magnitude. The concept of power, defined as the scalar product of force and velocity, is highlighted as a more effective way to analyze the energy transfer involved in these interactions.

PREREQUISITES
  • Understanding of electric charge and velocity vectors
  • Familiarity with the concepts of force and power in physics
  • Knowledge of the relationship between magnetic fields and electric charges
  • Basic grasp of infinitesimal calculus and its application in physics
NEXT STEPS
  • Study the principles of electric force and its role in charge motion
  • Learn about the effects of magnetic fields on charged particles
  • Explore the concept of power in physics and its calculation
  • Investigate the mathematical treatment of infinitesimals in physics
USEFUL FOR

Physics students, educators, and professionals interested in electromagnetism and the dynamics of charged particles.

Alex Schaller
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If an electric charge q is moving with a certain velocity v and we want to slow it down, this can only be done with an electrical force because magnetic force is perpendicular to displacement, correct? (watch video, time stamp 0:42)
video
 
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Yes. Although i see no video.
 
weirdoguy said:
Yes. Although i see no video.
It was only a pop video after all!
 
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Yes, I am thankful for whatever made it disappear.

Anyways, I wanted to write something in my first post, but I didn't, so I'll add it in this one, so that it's not completly useless:

Alex Schaller said:
force is perpendicular to displacement

This is true, but since this displacement is infinitesimal, I think that it is better to think in terms of velocity. Force is perpendicular to velocity at every instant, so it does not transfer energy, since it's power (scalar product of force and velocity) is zero. In general, keeping track of powers is easier than works done by forces.

I don't like infinitesimals.
 
The velocity of an electric charge is a vector quantity and it can be changed by a magnetic force.
 
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The direction can be changed. OP talked about slowing down, which means readucing magnitude of velocity, which can't be done by magnetic field.
 
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