-
Anonymous users2024-02-121.Two trains, the body length is 180 meters, from Beijing, Nanjing two places are relatively open, the speed is 90 kilometers per hour, two trains from each other, how many seconds?
90 km-h=90 1000 3,600=25 m/s.
180 2 (25 2) = seconds.
2.On the railway from Nanjing to Shanghai, a slow train is 150 meters long and travels 28 meters per second, and an express train is 120 meters long and travels 34 meters per second. The slow train is driving ahead, how many seconds does it take for the fast train to catch up to completely overtake the slow train?
150+120) (34-28) = 45 seconds.
3.Two trains are going in opposite directions, car A is 130 meters long, car B is 120 meters long, and the two trains meet each other and are separated from each other after 5 seconds. Knowing that car A travels 22 meters per second, find the speed of car B?
B velocity per second: (130 + 120) 5-22 = 28 meters.
4.The slow train is 90 meters long and the speed is 20 meters per second. The fast train is 110 meters long, and it took 20 seconds for the fast train to catch up and overtake the slow train. If these two trains are traveling in opposite directions, how long does it take to get from meeting each other and leaving completely?
The speed of the express train is (90 + 110) 20 + 20 = 30 meters per second.
Required: (90+110) (20+30)=4 seconds.
5.The fast and slow cars are 150 meters and 200 meters long respectively, and travel on a straight track in opposite directions. If the person sitting on the fast train sees the slow train passing through the window for 8 seconds, then how many seconds does it take for the person sitting on the slow train to see the fast train passing through the window?
The distance of the person on the express train is the length of the slow train.
The distance of the person on the slow train is the length of the fast train.
The speed of the two cars remains the same.
The time that a slow train sees is: 150 200 8 = 6 seconds.
6.An express train is 280 meters long and a slow train is 200 meters long, running in opposite directions on parallel tracks. From the two cars meet each other after 20 seconds of separation.
If two cars are driving in the same direction, the slow car is in front and the fast car is behind, and it takes 2 minutes to meet each other from each other. Find the speed of each car?
The sum of the speed of the two cars per second is: (280 + 200) 20 = 24 meters.
The difference in speed between the two cars is: (280+200) (2 60)=4 meters.
Express trains per second: (24+4) 2=14 meters.
Slow trains per second: (24-4) 2=10 meters.
-
Anonymous users2024-02-11Kilometer-hour = 25-meter-second.
180 25 = seconds.
2. (150+120) (34-28)=270 6=45 seconds.
3. (130+120) 5-22=28 m seconds.
4. (90+110) 20+20=30 m seconds.
90+110) (20+30) = 4 seconds.
8=25 m sec.
150 25 = 6 seconds.
6. The sum of the speed difference between the two cars is (280 + 200) 20 = 24 m seconds.
The speed difference between the two cars is (280+200) 120=4 meters and seconds.
Then the speed of the fast train is (24+4) 2=14 meters and seconds.
The speed of a slow train is 14-4=10 m/s.
-
Anonymous users2024-02-1060×2/3=40
1. There are up to 40 students who can enjoy both.
There is a minimum of 40 + 45 - 60 = 25 people.
2. There are 45-32=13 people who only love to play basketball.
There are 60-(45+40-32)= 7 people who don't like either.
-
Anonymous users2024-02-091. Go long.
requirements, the maximum possible overlap between these 2 3 and 3 4, that is, 2 3 60 = 40, because 2 3 3 4 within
At the very least, it is required that the smallest part of 2 3 and 3 4 coincide, 2 3 + 3 4-1 = 2 12, 6 5 12 = 25.
2. All love 32, that is, the part that they coincide with is 32, 32 60 = 8 15
3 4 60 = 45 people who love to play basketball, in fact, I feel that this question should make you ask for only love to play basketball, it should be.
60 (3 4-8 15) = 13.
I don't like it, it's that the two are added and subtracted, and then 60 is used to subtract this number, can you understand?
60-(45+40-32)=7 digits, done.
-
Anonymous users2024-02-081.60 bai2 3 = 40 people.
du 60 3 4 = 45 people.
The maximum number of zhi is 40 people, and the most dao version is 40 + 45-60 = 25 people 2 ①
Right 60 2 3 = 40 people.
40-32 = 8 people.
60-45-40+32=7 people.
-
Anonymous users2024-02-071.60 2 3 = 40 people 60 (2 3 + 3 4-1) = 25 people.
Up to 40 people, most.
There are 25 fewer specialists.
2.Genus 60 * 2 3 = 8 people.
40-32 = 8 people.
60-45-40+32=7 people.
1.The ratio is 2 times larger than the former term, and 3 times smaller than the latter term, and the ratio is 6 times the original ratio. >>>More
Assuming that the speed of A and B is that the distance between the two stations is Z, the first time is after the t1 time, and the second time is T2, when the first encounter, A and B have traveled the whole distance Z, because the first time they meet 12 kilometers west of the midpoint, and it is 12kmt1=z 2-12 xThe second meeting place is 20 kilometers away from the East Railway Station, and A has already traveled Z+20kmT2=Z+20 x The system of equations (Z 2-12) (x+y) x=Z can be obtained from the above; (x+y)(z+20) x=3zEquation2 Equation 1 yields (2z+40) (z-24)=3 and z=112
Answer] Typical pick-up questions.
Plan 1] Send a part of the people to 13 kilometers first, then return to pick up the other half of the people, and then both teams arrive at the same time. >>>More
The volume of a cuboid, a cube, or a cylinder can be calculated using the height of the base area. Two cylinders with equal surface area must have the same volume. If the height of a cylinder is expanded by 2 times, and the base area remains the same, its side area is also expanded by 2 times. >>>More
1.1026 (54+60)=9 minutes Calculate the time it takes for two people to meet from the beginning, that is, the time it takes for the dog to run, and then use this time * the dog's speed to know how many meters 70*9=630 meters. >>>More