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It takes 80 seconds for a train to pass through a 199 meter long railway bridge, and 72 seconds for it to pass through a 172 meter long tunnel at the same speed?
The speed of the fire vehicle is:
（199-172）÷（80-72）
=27÷8
=3.375 (M / s);
The vehicle length is:
three point three seven five × 80-199
=71 (m);
A: the speed of the train is 3.375 M / S; The train is 71 meters long
A train is 200m long. It passes through a 1.6km long bridge at the speed of 15m / s. how long does it take for the train to pass through the bridge?
The journey of the train through the bridge:
S = l bridge + L car = 1600m + 200m = 1800m,
Time when the train completely passed the bridge:
t=s
v=1800m
15m/s=120s=2min．
A: it took the train 2 minutes to pass the bridge
A 200m long train passes through a bridge at a constant speed of 54 kilometers per hour. It takes two minutes to find the length of the bridge
I haven't answered physics questions for a long time
For ease of understanding, they are all converted into international units
As the length of the train is 200m, the speed is 54km / h = 15m / s, and the passing time is 2min = 120s,
To calculate the length of the bridge, you need to know the distance and time that the train passes through the bridge. Now that the time is known, you only need to calculate the distance. However, the whole distance of the train passing through the bridge is calculated when the locomotive enters the bridge head and leaves the bridge tail. When the train tail leaves the bridge tail, the distance of the train is exactly the bridge length + train length, However, the actual length of the bridge is only that of the locomotive from the bridge head to the locomotive to the end of the bridge. Therefore, the distance required by the train first minus the length of the train is the length of the locomotive from the bridge head to the locomotive to the end of the bridge, that is, the length of the bridge
Distance traveled by train:
15m/s*120s=1800m
Calculate the length of the bridge based on the known length of the train
1800m-200m=1600m
So the length of the bridge is 1600 meters
When a train enters a 300m long tunnel, it takes 20 s from entering the tunnel to leaving completely. The time for the train to be completely in the tunnel is 10 s. ask for the length of the train
Set the conductor as XM,
List the equivalent relationship according to the constant speed: 300 + X
20=300−x
10，
De denominator: 300 + x = 600-2x,
The combined result of the transfer: 3x = 300,
The solution is: x = 100,
Then the length of the train is 100m
It takes 20 seconds for a train to travel at a constant speed through a 300m long tunnel. There is a lamp on the top of the tunnel, which shines vertically downward. The light shines on the train for 10 seconds, then the speed of the train is __
Suppose the length of the train is x, which means: 300 + X
20=x
10，
The solution is: x = 300,
Then the train speed is 300 ÷ 10 = 30m / s
A: the speed of the train is 30m / s
So the answer is: 30m / s
When a 300m long train passes through a 2000m long tunnel at the speed of 72km / h, how many s does it take for the train to pass through the tunnel and how long is the whole train in the tunnel
130S
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