At time t $=0,$ an electron with kinetic energy $16$ keV moves through x $=$ O in the positive direction of an x axis that is parallel to the

horizontal component of Earth's magnetic field. The field's vertical component is downward and has magnitude $74\mathrm{.}5$ T$.($a$)$ What is the magnitude of the electron's acceleration in meters per second squared, due to the magnetic field? $($b$)$ What is the electron's distance

from the x axis in centimeters when the electron reaches coordinate x $=16$ cm$?$