Question

magnetic force on charged particles conceptual question
part c
determine the direction of the force on the charge due to the magnetic field. note that the charge is negative (figure 3)
view available hint(s)
○ $vec{f}$ points out of the page
○ $vec{f}$ points into the page.
● $vec{f}$ points neither into nor out of the page and $vec{f}
eq0$
○ $vec{f} = 0$
incorrect; try again; 2 attempts remaining
if the charged particle in this situation were positive instead of negative, the force due to the magnetic field would be out of the page

Explanation:

Step1: Recall right - hand rule for magnetic force

The magnetic force on a charged particle is given by $\vec{F}=q\vec{v}\times\vec{B}$. For a positive charge, we use the right - hand rule: point the fingers of your right hand in the direction of $\vec{v}$ and curl them towards $\vec{B}$, and your thumb points in the direction of $\vec{F}$. For a negative charge, the force is in the opposite direction of what the right - hand rule gives for a positive charge.

Step2: Apply right - hand rule for positive charge

If the charge were positive, pointing the fingers in the direction of the velocity vector (diagonal upward) and curling them towards the magnetic field vector (left - ward), the thumb would point out of the page.

Step3: Adjust for negative charge

Since the charge is negative, the force is in the opposite direction. So the force points into the page.

Answer:

$\vec{F}$ points into the page.