A particle having a mass of 0.200 g carries a charge of ?2.34×10^?8 C. The particle is given an initial horizontal northward velocity of 4.00×10^4 m/s.
a) What are the direction of the minimum magnetic field that will balance the earth's gravitational pull on the particle? South, East, North, or West?
b) What are the magnitude of the minimum magnetic field that will balance the earth's gravitational pull on the particle?