![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
The train is 200 meters long. It takes 20 seconds to cross a 360 meter long bridge from the front to the rear. The train passes a 640 meter long bridge at the same speed A train with a body length of 200 meters passes through a 360 meter long bridge. It takes 20 seconds from the front of the train to the rear of the train. How long does it take for the train to pass through a 640 meter long tunnel at the same speed and enter from the front to the rear?
(200 + 360) divided by 20 = 28 meters (640 + 200) divided by 28 = 30 seconds
A: it takes 30 seconds from the front to the rear
A bridge is 1800 meters long. A train passes at a speed of 25 meters per second. The train is 200 meters long. How many seconds does it take to get on and off the bridge?
fast
Distance 1800 + 200, speed 25, time 2000 / 25 = 80 seconds
The speed of the 90 meter long train is 15 meters per second. It took him 14 seconds to catch up with and surpass the 50 meter long train. If the two trains were going in opposite directions, from meeting to leaving completely
It takes () seconds to turn on
Train speed = 15 - (90 + 50) △ 14 = 5m / S
Separation time = (90 + 50) / (15 + 5) = 7 seconds
The speed of a 90 meter long train is 15 meters per second. It took him 32 seconds to catch up with and surpass the 70 meter long train. If the two trains were going in opposite directions, they would meet each other from the front
It takes () seconds for the tail to leave completely
The other speed is 15 - (90 + 70) △ 32 = 15-5 = 10 m / s
Encounter time (90 + 70) △ 15 + 10) = 160 △ 25 = 6.4 seconds
The speed of a 90 meter long train is 15 meters per second. It takes 32 seconds for him to catch up with and surpass the 70 meter long train. If the two trains run in opposite directions, it takes (6.4) seconds from the front to the rear to leave completely
The speed of a 90 meter long train is 54 kilometers per hour. It took 14 seconds for it to catch up with and surpass the 50 meter long train,
How long does it take from meeting to leaving completely?
Solve by equation
Solution: the 14 seconds of this problem should be the time from catching up to exceeding. The two cars are traveling in the same phase. From catching up to exceeding 90 meters, the car walked 140 meters more
Set the speed of 50 long cars as v
54*1000/3600 * 14 - 14V = 140
Find v
Direct use time when 20% is opposite = 140 / (V + 54 * 1000 / 3600)
The speed of a 90 meter long train is 15 meters per second. It took 14 seconds for it to catch up with and surpass the 50 meter long train,
If the two trains are going towards each other, how many seconds will it take from meeting to leaving completely
The car overtook 90 + 50 = 140 meters from overtaking to completely overtaking
It took 14 seconds, so it's over 10 meters per second
The speed of the other car is 15-10 = 5 meters per second
Now we are going in opposite directions. The relative speed is the sum of the speeds of the two cars, 20 meters per second
From meeting to leaving completely, the car is 140 meters long
So it takes seven seconds
How long does it take for a 200m long light rail train to pass through a 2.8km overpass at a speed of 15mgs?
The distance for the train to completely pass the bridge: S = l bridge + L car = 200m + 2.8 × 103m = 3000m, the time for the train to completely pass the bridge: T = st = 3000m, 15m / S = 200s
How long does it take for a 200 meter long train to pass a 700 meter long cave at a speed of 54 kilometers per hour?
Speed = 54km / h = 900m / min
Distance through the cave = 200 + 700 = 900m
Passing time = 900 / 900 = 1min
That is 1 minute through
1. How many seconds does it take for a 200m long train to cross the 400m long bridge at the speed of 72km / h?
2. The record of a riding 45km in 3H and B running 400m in 1min 20s, which of them is faster?
3. When the car runs on the 90km highway, the speed of the first half of the journey is 6m / s, and the speed of the second half is 4m / s. The average speed of the whole journey is calculated
1.72km/h=20m/s
t=(200+400)/20=30s
2. V A = 45 / 3 = 15 km / h = 1500 / 60 m / min = 25 m / min > v b = 20 m / min
3. t=4500/6+4500/9=750+500=1250s
Average speed = 9000 / 1250 = 7.2m/s
It takes 21 seconds for a train to cross a 120 meter long bridge and 17 seconds to cross an 80 meter long bridge
(120-80) / (21-17) x21-120 = 90m
RELATED INFORMATIONS
- 1. When a railway bridge is 1000m long and a train with length of AM passes through the bridge, the speed of the train is measured to be 1 & nbsp; min from the beginning to the end of the bridge______ ．
- 2. How much speed does it take for a train to cross the railway bridge in 160m / S?
- 3. For example, how long does it take for a 300m long train to pass through a 1600m tunnel at a speed of 36km / h? How long does the whole train spend in the tunnel?
- 4. When a train passes a bridge at 2160m per minute, the time for the whole train to be completely on the bridge is 2
- 5. Emergency. The length of the train is 200m, the length of the bridge is 1000m, and the train passes through the bridge at a constant speed Emergency. The length of the train is 200m, the length of the bridge is 1000m, and the train passes through the bridge at a constant speed. (1) the time for the train to pass through the bridge? (2) what is the time for the train to finish at the bridge? (3) the time for the train driver to pass through the bridge? Note: This is a physics problem
- 6. How long does a 100 meter long train go through a 500 meter long cave at a speed of 72 km / h? Thank you
- 7. 4. A 200m long train runs at the speed of 36km / h. It takes 100s to pass through a cave. How many meters is the length of the cave
- 8. It takes 30 seconds for a train to cross the 430 meter long railway bridge. If the train speed doubles, It took 50 seconds for it to pass the 2180 meter iron bridge, so what's the length of the train
- 9. A 200m long train takes 45s to cross a 700 long bridge. What is the average speed of the train passing the bridge?
- 10. A train with a length of 300m crosses the bridge at a speed of 36km / h. It is known that it takes 5min for all trains to pass through the bridge, so the bridge length can be calculated rt
- 11. It took 60 seconds for the 1260 meter long bridge and 90 seconds for the 2010 meter long tunnel to cross emergency
- 12. The factory sent a car to pick up the factory director from his home on time. One day, the factory director walked to the factory one hour in advance. As a result, on the way to the factory, he met a car sent by the factory, so he arrived at the factory 10 minutes earlier than usual? （60 - 10÷2）÷（10÷2）= 11 My question is: where can I see that the long walking time is 55 minutes? But I still don't understand For example, when I go to work at 9 o'clock, the factory director leaves home at 8 o'clock. After 55 minutes, the factory director meets a car, which is already 8:55. Can the car arrive at the factory 10 minutes ahead of time?
- 13. When A-B / A + B = 4, find the value of 5 (a-b) / A + B + A + B / 2 (a-b) Those who answer will be rewarded
- 14. 1. The first n terms of a sequence and Sn = an ^ 2 + BN + C (a is not equal to 0) Ask (1) the formula an of the sequence; (2) whether the sequence constitutes the arithmetic sequence? 2. It is known that the sum of the first n terms of the sequence {an} is Sn and satisfies A1 = 1 / 2, an + 2snsn-1 = 0 (n > = 2) (1) Judge whether {1 / Sn} is arithmetic sequence and prove that (2) find Sn and an 3. In the natural number set y = f (x), we know that when x = 1, f (x) + F (x + 1) = 5, when x is odd, f (x + 1) - f (x) = 1, when x is even, f (x + 1) - f (3) = 3 (1) Verification: F (1), f (3), f (5) F (2n-1) (n ∈ n) is an arithmetic sequence; (2) Find the analytic expression of: F (x) thx! The third question should be: If x is odd, f (x + 1) - f (x) = 1; if x is even, f (x + 1) - f (x) = 3, and f (1) + F (2) = 5 (1) Prove f (1), f (3) F (2n-1) (n is a positive integer) is an arithmetic sequence (2) Finding the analytic expression of F (x)
- 15. A painting exhibition was held in Wuhan exhibition hall. 520 people came to visit the exhibition in the morning, 108 people left at noon, and 165 people came to visit in the afternoon. How many people visited the exhibition in the afternoon? How many people came to visit the exhibition on this day?
- 16. The little squirrel picked some mushrooms. Their water content is 99%. After a little drying, the weight is reduced by 5kg, so the water content is reduced to 98%? Put ideas and plans into practice. Write down
- 17. Xiao Ming didn't take his homework seriously. He took 6 as 0 and 1 as 7. The result is 137. Do you know the correct answer?
- 18. About time After 12 o'clock, when is the first time that the hour hand and minute hand coincide?
- 19. A mathematical problem about period~ If f (x) satisfies f (PX) = f (PX + 2P) (x ∈ R), then the period of F (x) is
- 20. computing time It takes an hour to burn a rope. Now there are n ropes of the same material thickness. How can we determine an hour and 15 minutes by burning a rope?