1. There are two trains, one is102m long, and it runs 20m per second. The length of the train is120m, and it runs at the speed of17m per second. Two cars are driving in the same direction. How many seconds does it take from the first train to catch up with the second train to the departure of the two cars?
2. Someone walks at a speed of 2 meters per second. A train came behind, which took 10 seconds longer than him. As we all know, this train is 90 meters long. Find the speed of the train.
At present, two trains run in the same direction at the same time. 12 seconds later, the express train overtook the local train. The express train runs18m per second, and the local train runs10m per second. If the tails of two trains are flush and driving in the same direction at the same time, the express train will overtake the local train after 9 seconds. Find the body length of two trains.
4. It takes 40 seconds for a train to cross a 440m bridge and 30 seconds for a 3 10/0m tunnel at the same speed. What is the speed and body length of this train?
Xiaoying and Xiao Min took two stopwatches to measure the speed and length of the passing train. Xiaoying used her watch to record that the time that the train passed in front of her was 15 seconds. Xiao Min used another watch to record that it took him 20 seconds to cross the first telephone pole in front and the second telephone pole in the back. It is known that the distance between two poles is 100 meters. Can you help Xiaoying and Xiao Min calculate the total length and speed of the train?
6. It takes 40 seconds for a train to cross a 530-meter bridge and 30 seconds to cross a 380-meter cave at the same speed. Find the speed and body length of this train.
7. The two started from two places along the path next to the railway line and walked at the same speed. A train came, 10 seconds. The whole train passed by A. Three minutes later, B met the train, and the whole train only took 9 seconds to pass by B. How long did the train leave B before they met?
8. Two trains, one with a length of120m and a speed of 20m per second; The other train is160m long and runs at a speed of15m per second. The two cars are driving in opposite directions. How many seconds does it take from the front meeting to the back leaving?
9. Someone walks at a speed of 2 meters per second. The train overtook him from behind 10 seconds. As we all know, the length of this train is 90 meters. Find the speed of the train.
10. Party A and Party B walk along the railway at the same speed. It took 8 seconds for a train to pass by Party A, and only 7 seconds to pass by Party B after leaving Party A for 5 minutes. How many minutes after Party B met the train?
Second, answer the question.
1 1. Fast train length182m, traveling 20m per second, slow train length1034m, traveling 8m per second. The two cars are parallel in the same direction. How long does it take for the express train to cross the local train when the rear of the express train meets the rear of the local train?
12. The length of the express train is182m, the length of the local train is1034m, and the speed of the local train is18m per second. The two cars are parallel in the same direction. How many seconds can an express train pass through the local train when the heads of the two cars are aligned?
13. A person is running along the railway at a speed of 120 meters per minute. A 288-meter-long train came from the opposite side. It took him 8 seconds to find the speed of the train.
14. A train is 600 meters long. It passes through a 200-meter-long tunnel at a speed of 10 meter per second. How long does it take to leave the tunnel from the front to the rear?
———————————— Answer the case ————————
Fill in the blanks
120m
102m
17x meter
20x meters
tail
tail
head
head
1. This topic is the catch-up problem of "two trains". Here "catching up" means that the head of the first train catches up with the tail of the second train, and "leaving" means that the tail of the first train leaves the head of the second train.
Suppose it takes x seconds from the first train catching up with the second train to the departure of the two trains, and the equation is:
102+ 120+ 17x = 20x
x =74。
2.
Assuming that the speed of the train is x meters per second, the equation is obtained.
10 x =90+2× 10
x = 1 1。
3.（
Then the express delivery length:18×12-10×12 = 96 (meters).
(2) the rear of the car is in a straight line and driving in the same direction at the same time, which is an express train.
Then the length of the local train is 18×9- 10×9=72 (meters).
4.( 1) The train speed is: (440-310) ÷ (40-30) =13 (m/s).
(2) The body length is: 13×30-3 10=80 (m).
5.( 1) The train speed is:100 ÷ (20-15) × 60× 60 = 72,000 (m/h).
(2) The body length is 20× 15=300 (m).
6. Set the train body to be x meters long and y meters long.
①②
solve
7. Let the train body be x meters long, A and B each walk y meters per second, and the train travels z meters per second. According to the meaning of the question, list the equations and get.
①②
①-②, so:
After the train left B, they met:
(seconds) (minutes)
8. Solution: The sum of the distances traveled by two cars is exactly the sum of the distances of two train conductors, so the time required to encounter the problem is: (120+60)? (15+20)=8 (seconds).
9. Think of it this way: when the train passes by people, their distance difference is the conductor. Divide the distance difference (90 meters) by the crossing time (10 second) to get the speed difference between the train and people. This speed difference plus the walking speed of people is the speed of the train.
90÷10+2 = 9+2 =11(m)
A: The speed of the train is 1 1 meter per second.
10. It is required that when A and B meet in a few minutes, the relationship between the distance between A and B and their speed must be found, which is related to the movement of the train. The distance between a and b can only be found by the movement of the train. The running time of the train is known, so it is necessary to find out its speed, at least the proportional relationship between it and the speeds of A and B. Because this question is more difficult.
① Find the relationship between the train speed and the speed of Party A and Party B, and let the train length be L, then:
(I) It takes 8 seconds for a train to pass through A, and this process is to catch up with the problem:
Therefore; ( 1)
(i i) It takes seven seconds for the train to pass through B. This process is a meeting problem:
Therefore. (2)
From (1) and (2),
So ...
(2) The distance between locomotive encounter A and train encounter B is:
.
③ Find the distance between A and B when the locomotive meets B. 。
After the locomotive meets A, it takes (8+5×60) seconds for the locomotive to meet B. Therefore, when the locomotive meets B, the distance between A and B is:
(4) How many minutes will A and B meet?
(seconds) (minutes)
A: In another minute, Party A and Party B will meet.
Second, answer the question.
11.1034÷ (20-18) = 91(seconds)
12.182 ÷ (20-18) = 91(seconds)
13.288 ÷ 8-120 ÷ 60 = 36-2 = 34 (m/s)
The speed of the train is 34 meters per second.
14. (600+200)10 = 80 (seconds)
Answer: It takes 80 seconds from the front of the car entering the tunnel to the rear leaving the tunnel.