Equations · Physics
Lorentz force
The force on a moving charge in electric and magnetic fields.
F = q(E + v × B)
Aethel says
F equals q times the quantity E plus v cross B
What it says
The electric field pushes the charge along the field. The magnetic field pushes it at right angles to both its velocity and the field, given by the cross product, so it bends the path without changing the speed.
Symbol by symbol
| Symbol | Say it | Means |
|---|---|---|
| q | q | the charge |
| E | E | the electric field |
| v × B | v cross B | the cross product of velocity and magnetic field |
More on×Times and cross product
Where you meet it
Electromagnetism, particle accelerators and electric motors.
Questions
How do you say Lorentz force out loud?
F = q(E + v × B) is read: “F equals q times the quantity E plus v cross B.” That is exactly what Aethel says when it meets the formula in a book.
What does q mean in Lorentz force?
q (said “q”) is the charge.
What does E mean in Lorentz force?
E (said “E”) is the electric field.
Can I listen to the equations in my own textbook like this?
Yes. Upload a PDF, EPUB or text file and Aethel reads it aloud with every equation spoken as maths, the way it reads this one, and highlights each sentence as it goes. You can start free.