Exercise $4$: Seesaw $-$ Modelling

Two bodies with masses $m_1$ and $m_2$ are coupled by a lever. The lever is considered mass$-$free and can pivot as shown in the sketch. A force $F_1$ is acting on the left mass $m_1$ as depicted. The right side of the lever is connected to a damper$-$element which applies a force $F_D=-D*v_2$ in the opposite direction as the movement $x_2$ of mass $m_2.$

Determine the block diagram of the system with input $F_1$ and output $x_2.$