Answer:
- z axis
Explanation:
The magnetic force is perpendicular to its speed and the direction of the magnetic field, its equation being
F = q v x B
Where the bold indicates vectors, q is a positive charge,
The way to use this equation is with the rule of the right hand, the thumb points in the direction of the velocity, the other fingers extended in the direction of the magnetic field and the palm is the direction of the force for a positive charge.
Let's apply this to our case the speed is on the x axis and the force in ex. negative Y axis, the other fingers point perpendicular to the sheet, but since the charge is negative the magnetic field enters the sheet, this would be the negative z axis