Exercise 2. A train is rolling at a constant speed. It takes 7 seconds to pass a fixed point by the track. On the other hand, from the moment the front of the train approaches an 870-meter bridge until the rear of the train leaves the bridge, 37 seconds elapse. Determine the length of the train, expressed in meters.
Solution to Exercise 2 The front of the train takes $37-7=30$ seconds to cross the bridge, so the length of the train is $\frac{7}{30} \times 870=203$ meters.