4 A car and its trailer travel along a straight, horizontal road. The coupling between them is light and horizontal. The car has mass 900 kg and resistance to motion 100 N , the trailer has mass 700 kg and resistance to motion 300 N , as shown in Fig. 4. The car and trailer have an acceleration of \(1.5 \mathrm {~m} \mathrm {~s} ^ { - 2 }\).
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{19d42df9-e752-4d33-85e1-4ec59b32135a-3_400_753_1037_657}
\captionsetup{labelformat=empty}
\caption{Fig. 4}
\end{figure}
- Calculate the driving force of the car.
- Calculate the force in the coupling.