Next to the railway line, there is a highway along the direction of the railway. On the highway, a tractor is driving at the speed of 20 kilometers per hour. At this time, a 370 meter long fire line is running It took 37 seconds for the train to pass by the tractor from the front to the rear. It was very urgent,

Next to the railway line, there is a highway along the direction of the railway. On the highway, a tractor is driving at the speed of 20 kilometers per hour. At this time, a 370 meter long fire line is running It took 37 seconds for the train to pass by the tractor from the front to the rear. It was very urgent,

It took 37 seconds for the train to pass by the tractor
Then the distance of tractor in 37 seconds is: 20000 / 3600 × 37 = 1850 / 9 (m)
As the length of the train is 370 meters, the distance of the train is: 370 + 1850 / 9 = 5180 / 9 (meters)
So the speed of the train is: 5180 / 9 △ 37 = 140 / 9 (M / s) = 56 (km / h)
A: the speed of the train is 56 km / h
Or use the speed difference upstairs to solve (but the one upstairs is wrong)
It took 37 seconds for the train to run 370 meters to catch up with the tractor
So trains are faster than tractors: 370 △ 37 = 10 (M / s) = 36 (km / h)
Then the train speed is: 36 + 20 = 56 (km / h)