A proton with charge q = +1.6 x 10" C and mass m = 1.67 x 10"kg is initially traveling horizontally in a magnetic field with velocity v = 800 m/s, as shown below. The proton experiences a downward acceleration due to gravity of g = 9.8 m/s . If the magnetic field were zero, the proton would follow the downward, parabolic trajectory shown in the dashed line. How large a magnetic field would have to be applied to force the proton to move in a straight line? B or O g QUESTION 10 [1 Mark] Which way would the field have to point