When at rest, a proton experiences a net electromagnetic force of magnitude 8.0 × 10-13 N pointing in the positive x direction. When the proton moves with a speed of 1.5 × 106 m/s in the positive y direction, the net electromagnetic force on it decreases in magnitude to 7.5 × 10-13 N, still pointing in the positive x direction. Find the magnitude and direction of

(a) The electric field

(b) The magnetic field.