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Xiao Ming is looking out of the window at the milestone. The number Xiao Ming sees at 12 o'clock is a two digit number, and the sum of the numbers is 7; the number he sees at 13 o'clock is the same as the previous number On the contrary, what you see at 14:00 is a three digit number, which is one more 0 than what you see at 12:00. Find the number you see at 12:00? (the car runs at average speed)
The number you see at 12 is 16
Let the one digit number seen at 12 o'clock be x and the ten digit number be y
10x+y-x-10y=100y+x-10x-y
x+y=6
x=1 y=6
Xiao Ming was riding in a car driving on the highway at a constant speed. At 9:00, Xiao Ming first observed that the milestone on the roadside was a double-digit number with ten digits and one
At 10:00, the second time we observed the two digits of the roadside milestone was exactly the two digit exchange position of the two digits we saw for the first time. The third time we saw that the milestone was three digits. This three digit is to add the number 0 to the middle of the two digits we saw for the first time to find the two digits Xiaoming saw for the first time
Let X be the number of ten digits you see for the first time
(10x+1)-(10+x)=(100+x)-(10x+1)
The solution is x = 6
So the first ten is 16
A. B, C three trains in a station (as shown in the figure), a train passengers see B train moving eastward, B train passengers see C train and platform are moving eastward, C train passengers see a train moving westward. Platform people see a, B, C three trains moving in what direction?
RELATED INFORMATIONS
- 1. When a train leaves from the station, it accelerates uniformly and moves in a straight line. When it starts, the operator on duty stands beside the front end of the first carriage. It takes 4 seconds for the first carriage to pass by him, and 20 seconds for the whole train to pass by him. The length of each carriage is equal, and the length of the carriage joint is not included. How many carriages are there in this train? How long does it take for the last nine carriages to pass by him
- 2. Xiao Ming sits at the window of the train. The train runs from the south section of the bridge to the north. Xiao Ming measures that it takes 80 seconds. His father asks Xiao Ming how long the bridge is, So Xiao Ming immediately timed the time from a certain pole beside the railway, and it took 25 seconds to measure the 10th pole. It is known that the interval between two adjacent poles is 50 meters. Xiao Ming calculated the length of the bridge. Then how long is the bridge?
- 3. When the train passes a bridge, Xiao Ming sits by the window. It takes 80 seconds to measure from his seat. His father asks Xiao Ming how long the bridge is. Xiao Ming starts to count the time from a certain pole beside the railway, and it takes 25 seconds for the tenth pole. If the distance between each two poles beside the railway is 50 meters, please help Xiao Ming calculate how long the bridge is
- 4. Xiao Yun sits at the window of the train. The train runs from the south end of the bridge to the north end. Xiao Yun measures that the time of sharing is 80 seconds. His mother asks Xiao Yun how long the bridge is, so ↓ Then above: Xiaoyun immediately clocks from a certain pole beside the railway, and it takes 25 seconds to reach the 10th pole. If the distance between each two poles is 50 meters, Xiaoyun can calculate the length of the bridge. Then, how long is the bridge?
- 5. The length of the fast and slow trains are 150 meters and 200 meters respectively. They run on parallel tracks. If it takes 6 seconds for people on the slow train to see the fast train passing the window, what is the time for people on the fast train to see the slow train passing the window______ Seconds
- 6. If we want to watch the lunar phase on the seventh night of the lunar new year, we should choose () observation A. The eastern sky in the first half of the night B. The western sky in the first half of the night C. The eastern sky in the middle of the night I'll help you with the price
- 7. What is the phase of the moon on the day of the eclipse
- 8. Science question: May 2013 is March 22 of the lunar calendar. What is the phase of the moon on this day?
- 9. The lunar phase on August 8, 2008 (the first day of the seventh lunar month) is the closest to ()?
- 10. What is the phase of the moon on the night of the eclipse? Why?
- 11. When Xiao Ming was on the train, the first time Wang looked out of the window, he happened to see that the number of kilometers on the roadside milestone was one by one, and the number was six double digits When you look out, you can see that the kilometer on the roadside milestone is just the original two digit number, and the front and back positions have been exchanged; when you look out of the car window after another 20 minutes, the kilometer on the roadside milestone is a three digit number, and it's just the middle of the two digit number you see for the first time, with an extra 0. According to the above information, calculate the train speed When Xiao Ming took the train, when he looked out of the window for the first time, he saw that the number of kilometers on the roadside milestone was two digits of six. When he looked out of the car again, he saw that the number of kilometers on the roadside milestone was just the original two digits, and the front and back positions were exchanged. After 20 minutes, when he looked out of the window again, the number of kilometers on the roadside milestone was three digits, According to the above information, the train speed can be calculated
- 12. A train runs at a constant speed on a flat track, and a passenger drops two objects a and B from the window. If the air resistance is negligible, what will happen when they fall freely () A. A is directly below B B. A is directly behind B C. A is under the front of B D. A is under the back of B I want a solution But I lost it in different order.
- 13. An observer on the platform stood at the front of the first carriage as the train started There is an observer on the platform. When the train starts, he stands near the front end of the first carriage. The first carriage passes him in 10 seconds. Suppose the train moves in a straight line with uniform acceleration, what is the time interval for the seventh carriage to pass him? If there are 10 carriages, what is the time interval for all the carriages to pass him/
- 14. If a person throws an object horizontally towards the rear of the train in the train carriage, what can another person standing on the ground platform see the trajectory of the object
- 15. There is an observer on the train platform. When the train starts, he just stands at the front end of the first carriage. After the train starts, he accelerates evenly. After 4 seconds, the first carriage passes the observer, and the time for the whole train to pass the observer is 20 seconds. If each carriage is equal in length and the length of carriage connection is not taken into account, we can find: (1) how many carriages are there in this train; (2) the last 9 carriages pass the observer The time experienced by the observer
- 16. When passengers on the train look out of the window, the trees on both sides of the railway quickly retreat. What is the reference for passengers to choose
- 17. The length ratio of a and B trains is 4:5. They travel in the same direction. Xiaoming on car a sees that car B has passed from back to front for 20 seconds. How many seconds does Xiaodong on car B see that car B has passed car a?
- 18. The length of a and B buses are 150 meters and 200 meters respectively. They are running on parallel tracks. It is known that a passenger on car a has measured that the time for car B to pass outside his window is 10 seconds, so what is the time for the passenger on car B to see car a pass outside his window______ Seconds
- 19. When a person is sitting in a car, what does it mean if he sees the scenery moving backward out of the window
- 20. The two trains are both 180 meters long. If the two trains run in opposite directions, it will take 12 seconds from the front to the trunk. If they run in the same direction, it will take 60 seconds from the front of a to the rear of B until the rear of a exceeds the front of B. assuming that the speed of a and B is constant, calculate the respective speed of the two trains