6.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{6fb27fe5-055a-4701-bd80-e66ebd57292a-4_252_726_194_561}
\captionsetup{labelformat=empty}
\caption{Fig. 2}
\end{figure}
Figure 2 shows a picnic bench of mass 20 kg which consists of a horizontal plank of wood of length 2 m resting on two supports, each of which is 0.6 m from the centre of the plank.
Luigi sits on the bench at its midpoint and his mother Maria sits at one end. Their masses are 40 kg and 75 kg respectively.
By modelling the bench as a uniform rod and Luigi and Maria as particles,
- find the reaction at each of the two supports.
Luigi moves to sit closer to his mother.
- Find how close Luigi can get to his mother before the reaction at one of the supports becomes zero.
- Explain the significance of a zero reaction at one of the supports.