A $\backslash (36-\backslash$mathrm$\{$kg$\}\backslash )$ girl stands on a $\backslash (8-\backslash$mathrm$\{$kg$\}\backslash )$ wagon holding two $\backslash (15\mathrm{.}0-\backslash$mathrm$\{$kg$\}\backslash )$ weights. She throws the weights horizontally off the back of the wagon at a speed of $\backslash (4\mathrm{.}0\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash )$ relative to herself.

Assuming that the wagon was at rest initially, what is the speed of the girl after she throws both weights at the same time?

Assuming that the wagon was at rest initially, what is the speed with which the girl will move after she throws the weights one at a time, each with a speed of $4\mathrm{.}0\backslash (\backslash$mathrm$\{$m$\}/\backslash$mathrm$\{$s$\}\backslash )$ relative to herself?