A proton, with mass 1.67 x 10-27 kilogram and charge +1.6 x 10-19 C, is sent with velocity 7.1 x 104 meter per second in the +x direction into a region where there is a uniform electric field of magnitude 730 V/m in the +y direction. Suppose that the magnetic field has no x-component and neglect gravitational effects. Obtain the magnitude and direction of the uniform magnetic field in the region, if the proton is to pass through undeflected?