Anegative charge q = − 3.20 × 10 ^− 6 c q=−3.20×10−6c is located at the origin and has velocity → v = ( 7.50 × 10 4 m / s ) ^ ı + ( − 4.90 × 10 4 m / s ) ^ ȷ v→=(7.50×10^4m/s)ı^+(−4.90×10^4m/s) ȷ^ . at this instant what is the magnetic field produced by this charge at the point x = 0.250 m x=0.250m , y = − 0.330 m y=−0.330m , z = 0 z=0 ?