The intensity of the magnetic force F experienced by a charge q moving with speed v in a magnetic field of intensity B is equal to
where
is the angle between the directions of v and B.
1) Re-arranging the previous formula, we can calculate the value of the magnetic field intensity. The charge is
. In this case, v and B are perpendicular, so 
, therefore we have:
2) In this second case, the angle between v and B is
. The charge is now 
, and the magnetic field is the one we found in the previous part, B=2.8 T, so we can find the intensity of the force experienced by this second charge:
where
1) Re-arranging the previous formula, we can calculate the value of the magnetic field intensity. The charge is
2) In this second case, the angle between v and B is