An electron in a cathode$-$ray tube accelerates uniformly from $2\mathrm{.}00104/$ to

$6\mathrm{.}00106/$ over $1\mathrm{.}50$ cm$.$

$($a$)$ In what time interval does the electron travel this $1\mathrm{.}50$ cm$?$

$($b$)$ What is its acceleration?