$(50)$ Work is done on a cart along a line in one direction $($called x$)$ given by F$($x$)=10$ N m$3$ x $3.$ The cart travels at vx $=4\mathrm{.}0$m$/$s at x$=0.$ At what location will it be traveling at $20$m$/$s$?$ If the cart has a mass of $10$kg$,$ how much energy did it gain in traveling from x$=0$m to x$=10$m$?$