4.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{d9615c4f-d8fa-4e44-978a-cf34b2b1c0b5-10_211_1527_294_269}
\captionsetup{labelformat=empty}
\caption{Figure 2}
\end{figure}
A car of mass 1200 kg is towing a trailer of mass 400 kg along a straight horizontal road using a tow rope, as shown in Figure 2.
The rope is horizontal and parallel to the direction of motion of the car.
- The resistance to motion of the car is modelled as a constant force of magnitude \(2 R\) newtons
- The resistance to motion of the trailer is modelled as a constant force of magnitude \(R\) newtons
- The rope is modelled as being light and inextensible
- The acceleration of the car is modelled as \(a \mathrm {~m} \mathrm {~s} ^ { - 2 }\)
The driving force of the engine of the car is 7400 N and the tension in the tow rope is 2400 N .
Using the model,
- find the value of \(a\)
In a refined model, the rope is modelled as having mass and the acceleration of the car is found to be \(a _ { 1 } \mathrm {~ms} ^ { - 2 }\)
- State how the value of \(a _ { 1 }\) compares with the value of \(a\)
- State one limitation of the model used for the resistance to motion of the car.