4.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{34fc8023-cf31-420a-bb92-a31735fe5bdb-08_225_1239_280_413}
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\caption{Figure 2}
\end{figure}
Figure 2 shows a car towing a trailer along a straight horizontal road.
The mass of the car is 800 kg and the mass of the trailer is 600 kg .
The trailer is attached to the car by a towbar which is parallel to the road and parallel to the direction of motion of the car and the trailer.
The towbar is modelled as a light rod.
The resistance to the motion of the car is modelled as a constant force of magnitude 400 N .
The resistance to the motion of the trailer is modelled as a constant force of magnitude R newtons.
The engine of the car is producing a constant driving force that is horizontal and of magnitude 1740 N.
The acceleration of the car is \(0.6 \mathrm {~ms} ^ { - 2 }\) and the tension in the towbar is T newtons.
Using the model,
- show that \(\mathrm { R } = 500\)
- find the value of T .
At the instant when the speed of the car and the trailer is \(12.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\), the towbar breaks.
The trailer moves a further distance d metres before coming to rest.
The resistance to the motion of the trailer is modelled as a constant force of magnitude 500 N.
Using the model, - show that, after the towbar breaks, the deceleration of the trailer is \(\frac { 5 } { 6 } \mathrm {~ms} ^ { - 2 }\)
- find the value of d.
In reality, the distance d metres is likely to be different from the answer found in part (d).
- Give two different reasons why this is the case.