A proton is moving left through a magnetic field directed up toward the ceiling. In what direction is the magnetic force towards the proton?

Correct answer: The proton moves toward the wall in front of the observer

Explanation:

The proton is affected by the Lorentz force calculated by the formula:

Fl = q · (V * B) = q · V · B · sin φ

where is:

q - in this case proton charge

V - the velocity of the particle in this case proton

B - magnetic induction magnitude

φ - angle between velocity and magnitude of magnetic induction

i this case φ = 90° ⇒ sin φ = 1

Fl = q · V · B

The direction of the Lorentz force acting on the positively charged particle coincides with the direction of forward motion of the right screw relative to the plane formed by the velocity and magnetic induction.

So the proton moves toward the wall in front of the observer.

God is with you!