Blocks $\backslash (\backslash$boldsymbol$\{$A$\}\backslash )($mass $2\mathrm{.}00$ kg $)$ and $\backslash (\backslash$boldsymbol$\{$B$\}\backslash )($mass $6\mathrm{.}00$ kg $)$ move on a frictionless, horizontal surface. Initially, block $\backslash (\backslash$boldsymbol$\{$B$\}\backslash )$ is at rest and block $\backslash (\backslash$boldsymbol$\{$A$\}\backslash )$ is moving toward it at $\backslash (4\mathrm{.}00\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash ).$ The blocks are equipped with ideal spring bumpers. The collision is head$-$on$,$ so all motion before and after the collision is along a straight line. Let $\backslash (+\backslash$boldsymbol$\{$x$\}\backslash )$ be the direction of the initial motion of block $\backslash ($ A $\backslash ).$