A rectangular prism $($mass $M=4kg,$ height $H=0\mathrm{.}5m)$ is at rest on a frictionless horizontal plane. There is a second similarly shaped prism

$($mass $m=1kg,$ height $\frac{H}{2}=0\mathrm{.}25m)$ positioned on the inclined plane of the first prism and this is also at rest. There is no friction between the prisms. A spring with spring constant $80\frac{N}{m}$ and undeformed length $L=H=0\mathrm{.}5m$ is connecting the two prisms. At $t=0,$ the system is in situation I $($top figure$).$

Part A

Determine the velocities of both prisms in situation II$,$ indicated in the bottom figure.

$v_M=$

The prism moves to the left

The prism moves to the right

$v_{m,x}=$

$v_{m,y}=$

Part B

For situation II$,$ write down all equations needed to determine every force on the prisms, as well as their accelerations.