A $144-$g baseball moving $28\mathrm{.}0$ m$>$s strikes a stationary

$4\mathrm{.}85-$kg brick resting on small rollers so it moves without

significant friction. After hitting the brick, the baseball bounces

straight back, and the brick moves forward at $1\mathrm{.}10$ m$>$s$.$

$($a$)$ What is the baseball$$s speed after the collision? $($b$)$ Find

the total kinetic energy before and after the collision.