Two cars traveling in the same direction on the highway

It's the sum of two car lengths.

Calculate the length of the car during the period, and then subtract the distance.

The speed of car A is a and the length of car is A1

The speed of car B is B, and the length of car is B1

Car A wants to overtake A is greater than or equal to B The overtaking distance is A1+B1, which is to find the speed problem The distance traveled by car A is over B.

Find the time taken in the overtaking process first: (a1+b1) (a-b) distance is time multiplied by speed: (a1+b1) (a-b) x a The formula derivation is not easy to write, so bring in the numbers.

The first car is 100km h and 5 meters long.

Car B is 80km h 4m long.

Car A travels a distance.

100000-80000) (seconds.)

Rice. The distance traveled by car B.

100000-80000) (seconds.)

Rice. m is the same as the length of the car.

Of course, it is better to derive with algebraic formulas.

The length of the two cars is a+b, and the speed difference between the two cars is set to x, then it takes (a+b) x time to overtake, and the distance difference between the two cars is the speed difference multiplied by the time = x * (a+b) x, so the distance difference is equal to the length of the two cars.

The two cars walked opposite each other to explain.

Driving in the opposite direction: driving in the opposite direction is that two cars are driving in opposite directions, as demonstrated in the animation 2 3 in the same direction, reading Zheng lead: driving in the same direction, which means that two cars are driving in one direction, watching the animation demonstration of mathematics - Jingdong big brand convergence, quality assurance, praise and full, click in to buy advertising 3 3 3 driving in the back direction:

It is good to drive with your back to the cong model, that is, two cars or two people walking in opposite directions.

If the distance length is x (km), the length of ordinary highway (x-60) is 2km, and the length of highway is x 2+30km

then [(x-60) 2] 60+(x 2+30) 100=3

Q: How many hours does the highway take, but what about the ordinary road?

Solution: The highway was opened for x hours, and the ordinary highway was opened for (3-x) hours.

100x-60（3-x）=60

x = A: ......No plagiarism.

A, B, 0 time two cars at the same time through the same road sign next to the highway, in 0-10s the speed of car B is greater than the speed of car A, the two cars gradually move away, in 10-15s the speed of car B is less than the speed of car A, the two cars gradually approach, so 10s apart from each other the farthest so A is wrong, B is correct

c. According to the "area" of the velocity image to represent the displacement, it can be seen from the geometric knowledge that the displacement of the two cars is equal in 5-15s, but the displacement of B is large in 15s, and the two cars do not meet, so C is wrong

D. From the above analysis, it can be seen that in 0-20 s, car B is always in front of car A, and the displacement of the two cars passing through is equal at 20s, so the two cars meet so D is wrong so B is selected

12 (hours Sakura);

Answer: When the first time we met, the two cars had been traveling for 12 hours

3 (72-60) = hours = 15 minutes is another 15 minutes Car B can catch up with car A...

3 15=km Kilometers apart.

It can be reversed, that is, to find the difference of 1 minute:

Distance difference = speed difference * time.

1 minute = 1 60 hours.

km) or: 72 60-60 60

km).

There were 100 peaches on the tree.