Calculate the magnitude of the magnetic force acting on the proton? If it moves with a speed of $1\mathrm{.}0$x $10^5$m$/$s through the Earths magnetic field, which has a value of $55\mathrm{.}0$x$10^-6$ at a particular location. when the proton moves westward the magnetic force acting on it is directed straight upward, and when it moves northward, no magnetic force across on it$.$a$)$ what is the direction of the magnetic field, and b$)$ what is the strength of the magnetic force when the proton moves eastward