Last wagon

A 200 m long train passes through the 700 m long tunnel so that a time of 1 minute elapses from the entry of the locomotive into the tunnel to the exit of the last wagon from the tunnel. Find the speed of the train.

Correct answer:

v =  15 m/s

Step-by-step explanation:

$$\begin{gathered} a=700\text{m} \\ b=200\text{m} \\ t=1\text{min}\to \text{s}=1\cdot 60\text{s}=60\text{s} \\ s=a+b=700+200=900\text{m} \\ v=\frac{s}{t}=\frac{900}{60}=15\text{m/s} \end{gathered}$$

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