When at rest, a proton experiences a net electromagnetic force of magnitude 8.0E-13 N pointing in the positive x-direction. When the proton moves with a speed of 1.5E6 m/s in the positive y-direction, the net electromagnetic force on it decreases in magnitude to 7.5E-13 N, still in the positive x-direction. a)What is the magnitude and direction of the electric and magnetic fields? b)what is the magnitude and direction of the b field