Going in Magnetic Circles

A proton enters a uniform magnetic field of 0.35 T with a velocity of 4.7e6 m/s. (The mass of a proton is 1.67e-27 kg.)

1. Describe the motion of the particle, in particular the direction of the magnetic force relative to the direction of motion. Make sure you state your assumptions.
   
   
   
2. Mathematically characterize the motion.