A proton moves through a uniform magnetic field given by B $=(15\mathrm{.}01-25\mathrm{.}4]+12\mathrm{.}75)$ mT$.$ At time ta$,$ the proton has a velocity

givenby $0=0$xi $+0,+(1\mathrm{.}94$ km$/$s$)$k and the magnetic force on the protonis F B $=(5\mathrm{.}3310-17$ N$+(3\mathrm{.}1510-17$ N$/$J$.$

$($a$)$ At that instant, what is vx$?($b$)$ At that instant, what is vy$?$