As shown in the figure, a small particle of charge q= -7.0 x 10-6C and mass m= 3.1 x 10-12kg has velocity vo= 11.2 x 103m/s as it enters a region of uniform magnetic field. The particle is observed to travel in the semicircular path shown, with radius R= 5.0 cm. Calculate the magnitude and direction of the magnetic field in the region.