Halliday, Resnick & Walker — Oscillations: Problem Problem_67

In Fig. 15.32, three 10,000 kg ore cars are held at rest on a mine railway using a cable that is parallel to the rails, which are inclined at angle \(\theta = 30^\circ\). The cable stretches 15 cm just before the coupling between the two lower cars breaks, detaching the lowest car. Assuming that the cable obeys Hooke’s law, find the (a) frequency and (b) amplitude of the resulting oscillations of the remaining two cars.