Analysis: trucks and buses leave the two places at the same time. Six hours later, the distance between the two cars is still 20 kilometers. 7 10 km MINUS 20 km is the road that two cars have traveled in 6 hours. It is also known that the speed of the passenger car is 55 kilometers per hour, and the speed of the truck can be obtained.
Solution: (710-20)+6-55 = 690+6-55 =115-55 = 60 (km).
The speed of this truck is 60 kilometers per hour.
Example 2: The railway engineering team plans to dig a 200-meter-long cave. Team A digs 1.2 meters every day from one side of the mountain, and Team B digs 1.3 meters every day from the other side of the mountain. How many days does it take to dig this cave at the same time?
Solution: 200+(1.2+1.3) = 200+2.5 = 80 (days)
It takes 80 days to dig through this cave.
Example 3: Two students, A and B, go to the Youth Activity Center from school. A walks 60 meters per minute, and B walks 50 meters per minute. After B walked for 4 minutes, A began to walk. How many minutes does it take for A to catch up with B?
Analysis: "A didn't leave until B left for 4 minutes" means that B was not at school when A left. (50X4=) 200. A walks more than B per minute (60-50=) 10 meter. So we can find out the time it takes for A to catch up with B?
Solution: 50X4+ (60-50)=200/ 10=20 (minutes)
A: It takes 20 minutes for A to catch up with B. ..
Example 4: Zhang and Li walked in opposite directions from A and B respectively at the same time. Zhang walks 5 kilometers per hour and Li walks 4 kilometers per hour. After meeting for the first time, they walked on. When Zhang went to B, he immediately returned at the original speed. Li went there and immediately returned at the same speed. They walked for four hours from the beginning to the second meeting. How many kilometers is it between A and B?
Analysis: Draw a line chart first. From the picture, we can see that the sum of the distances that Zhang and Li walked from the beginning to the second meeting should be three times the distance between A and B, which is the key to solve this problem.
Solution: (5+4) * 4/3 = 9 * 4/3 = 36/3 =12 (km1)
A: the distance between a and b is 12km.
Example 5: A good horse walks 1.20 kilometers every day, while a bad horse walks 75 kilometers every day. Bad horses go first 1.2 days. How many days can a good horse catch up with a bad horse?
How many kilometers can a bad horse walk 1 2 days? 75x12 = 900km.
(2) How many days does a good horse catch up with a bad horse? 900/( 120-75) =20 (days)
The comprehensive formula is 75x12/(120-75) = 900+45 = 20 (days).
A: A good horse can catch up with a bad horse in 20 days.
Example 6: Xiaoming and Xiao Liang are running on the 200m circular track. Xiao Ming ran for 40 seconds. They started from the same place and ran in the same direction at the same time. Xiaoming ran 500 meters when he first caught up with Liang Xiao. What is the speed of Xiao Liang per second?
Solution: When Xiao Ming caught up with Xiao Liang for the first time, he ran one lap more than Liang Xiao, that is, 200 meters. At this time, Xiao Liang ran (500-200m). To know the speed of Xiao Liang, we need to catch up with the time, that is, Xiaoming runs 500 meters. I also know that it takes 40 seconds for Xiao Ming to run 200 meters and [40X (500+200)] seconds for 500 meters, so the speed of Xiao Liang is:
(500-200) Six [40x (500+200)] = 300+100 = 3 (m)
The speed of Xiao Liang is 3 meters per second.
Example 7: My younger brother and sister go to school from home at the same time. My brother walks 90 meters per minute and my sister walks 60 meters per minute. When my brother arrived at the school gate, he found that he had forgotten his textbook. He immediately went home to get it along the original road and met his sister at 0/80 meters away from the school/kloc-. How far is their home from school?
Solution: You need to know the distance and speed, so the key is to find the meeting time. According to the question, in the same time (from departure to meeting), my brother walked (180X2) meters more than my sister, because my brother walked (90-60) meters more than my sister every minute.
Then, they need 180X2+ (90-60) = 12 (minutes) to meet from home to school, and the distance from home to school is 90X 12- 180=900 (meters).
A: My home is 900 meters from school.
Example 8: A bus travels from Station A to bilibili at a speed of 48 kilometers per hour; A truck was traveling from bilibili to Station A at the same time, with a speed of 40 kilometers per hour. Two trucks meet at the midpoint of two stations 16 km, and find the distance between the two stations.
Solving this problem can change from meeting a problem to chasing it. It can be seen from the title that the bus lags behind the truck (16X2) kilometers, and the time when the bus catches up with the truck is the aforementioned meeting time, that is, 16X2+ (48-40) =4 (hours).
So the distance between the two stations is (48+40) x4 = 352 (1000m).
Column into a comprehensive formula (48+40) x [16x2+(48-40)] = 88x4 = 352 (km).
A: The distance between Station A and bilibili is 352 kilometers.