A Proton, with Mass 1 $2.3 \times 10 ^ { 4 } \mathrm {~m} / \mathrm { s }$

Short Answer

A proton, with mass 1.67 × 10^-27 kg and charge +1.6 × 10^-19 C, is sent with velocity $2.3 \times 10 ^ { 4 } \mathrm {~m} / \mathrm { s }$ in the +x direction into a region where there is a uniform electric field of magnitude $780 \mathrm {~V} / \mathrm { m }$ in the +y direction. What must be the magnitude and direction of the uniform magnetic field in the region if the proton is to pass through undeflected? Assume that the magnetic field has no x component and neglect gravitational effects.