# A group of particles is traveling in a magnetic field of unknown magnitude and direction. You observe that a proton

A group of particles is traveling in a magnetic field of unknown magnitude and direction. You observe that a proton moving at 1.50 km/s in the +x-direction experiences a force of 2.25 \times 10^{-16} N2.25×10 −16 N in the +y-direction, and an electron moving at 4.75 km/s in the -z-direction experiences a force of 8.50 \times 10^{-16} \mathrm{N}8.50×10 −16 N in the +y-direction.

(a) What are the magnitude and direction of the magnetic field?
(b) What are the magnitude and direction of the magnetic force on an electron moving in the -y-direction at 3.20 km/s?