(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Three identical train cars, coupled together, are rolling east at 3.71 m/s. A fourth car travelling east at 6.74 m/s catches up with the three and couples to make a four-car train. A moment later, the train cars hit a fifth car that was at rest on the tracks, and it couples to make a five-car train. All 5 cars are identical. What is the speed of the five-car train?

2. Relevant equations

m1v1+m2v2+... = m1v1'+m2v2'+...

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# Homework Help: Conservation of Momentum question

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