Electromagnetic Forces

Coulomb electrostatic force and full Lorentz force on moving electric charges.

General idea of the topic

This sub-block connects the force between point charges with the dynamics of charged particles in the presence of combined electric and magnetic fields, from Coulomb's law to the Lorentz force.

It analyses how the direction, magnitude and sense of the force depend on the field geometry and the charge velocity, determining rectilinear, circular or helical trajectories depending on the case.

What you will truly understand

• When to use Coulomb and when to use Lorentz.
• How the direction and magnitude of the force change according to field geometry.
• How to interpret radius and cyclotron frequency in charged-particle motion.

Recommended learning route

1. Electric force on charge pairs and in a given field.
2. Lorentz force and its electric/magnetic components.
3. Comparison of domains of validity in real applications.

Physical criterion you must acquire

Separate magnitude, direction and sense of each contribution before adding or interpreting a trajectory.

Connection with real problems

Spectrometry, accelerators, electrostatic filtering and precision sensors use this block directly.

Final goal of the topic

Solve electromagnetic interactions with vector control, unit consistency and model validity criteria.