1. The problem statement, all variables and given/known data A particle enters perpendicular to a magnetic field with a speed of 100,000 m/s. The magnetic field has a strength (B) of 0.80 T. The particle starts doing a spinning motion with an 0.1m radius. The particle charge is +3e (three elementary charges). Calculate the mass of the particle. 2. Relevant equations Since it does a spinning motion, we need the formula for centripetal motion. F=m(v^2/r). We also need a formula that gives us F based on B and Q (charge) and v (speed). For that we have F = QvB. 3. The attempt at a solution We set them equal. m(v^2/r)=QvB and we can take off one v. m(v/r)=QB, we move the things around so we have m alone m*v = rQB => m = rQB / v We enter everything that is known and we get: 0.1 * (3*1.6*10^-19) * 0.80 split by 100,000. Result: 3.84 × 10^-25 kg. Am I correct?