Q$1[$Type B$]$: In an amusement park, two bumper cars are moving toward each other on a flat, frictionless surface. Car A has a mass of $200$ kg $($including the rider$)$ and is traveling at a speed of $\backslash (4\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash ),$ while Car B has a mass of $300$ kg $($including the rider$)$ and is traveling at a speed of $\backslash (2\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash )$ in the opposite direction. The two cars collide elastically $($energy is conserved$).$ What are the speeds of Car A and Car B right after the collision?

Hint: Is the momentum of the two cars as a system conserved?