A Proton, with Mass $1.67 \times 10 ^ { - 27 } \mathrm {~kg}$

Short Answer

A proton, with mass $1.67 \times 10 ^ { - 27 } \mathrm {~kg}$ and charge $+ 1.6 \times 10 ^ { - 19 } \mathrm { C }$ , 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.