1) Magnitude
The magnetic force acting on a moving charge is given by:

where
q is the charge of the particle
v is its speed
B is the magnitude of the magnetic field
is the angle between the directions of v and B.
In this problem, we have a proton, so the charge is
; its speed is
, while the magnetic field is
. The angle is
, because the proton is moving perpendicular to the magnetic field. Therefore, if we substitute these data into the previous equation, we find:

So, the magnitude of the force is
.
2) Direction
The direction of the force can be determined using the right-hand rule:
- index finger: direction of the velocity (eastward)
- middle finger: direction of the magnetic field (northward)
- thumb: direction of the force (upward).
So, the direction of the force is upward.