Question

175 БАЛЛОВ ЗА РЕШЕНИЕ!!Грузовая машина проезжает расстояние между двумя городами за 18 ч , а легковая - за 9 ч. Машины одновременно выехали из двух городов навстречу друг другу . Чере сколько часов они встретятся

Answer 1

Путь всё расстояние равняется 1км
Тогда скорость грузовика:1/18км/ч(Так как грузовик за 18 часов проходит всё расстояние)
Скорость автомобиля: 1/9км/ч(Так как автомобиль за 9 часов проходит всё расстояние)
1/9+1/18=3/18=1/6км/ч(Совместная скорость)
1/(1/6)=6ч
Ответ:Через 6 часов

Answer 2

Расстояние между городами возьмем за 1
скорость Грузовой будет 1/18 км/ч
скорость легковой будет 1/9 км/ч
Общая скорость:
$\frac{1}{18} + \frac{1}{9} = \frac{3}{18} = \frac{1}{6}$км/ч, 
$1: \frac{1}{6}$=6 часов

Answer 3

Problem Analysis

We are given that a truck travels a distance between two cities in 18 hours, while a car travels the same distance in 9 hours. Both vehicles start from their respective cities and travel towards each other. We need to determine how many hours it will take for them to meet.

Solution

To solve this problem, we can use the concept of relative speed. The relative speed is the sum of the speeds of the two vehicles. Let's denote the speed of the truck as T and the speed of the car as C.

We know that the distance traveled by the truck is the same as the distance traveled by the car. Let's denote this distance as D.

We can use the formula: time = distance / speed to find the time taken by each vehicle.

For the truck: 18 = D / T (Equation 1)

For the car: 9 = D / C (Equation 2)

To find the time it takes for the vehicles to meet, we need to find the time it takes for them to cover the entire distance between the two cities. This can be calculated by adding the times taken by the truck and the car.

Let's solve the equations to find the values of T and C.

From Equation 1, we can express D in terms of T: D = 18T

Substituting this value of D into Equation 2, we get: 9 = (18T) / C

Simplifying, we find: C = 2T (Equation 3)

Now we have two equations: Equation 1 and Equation 3. We can substitute the value of C from Equation 3 into Equation 1 to solve for T.

Substituting C = 2T into Equation 1, we get: 18 = D / T 18 = (18T) / T

Simplifying, we find: 18 = 18

This equation is true for any value of T. Therefore, we can conclude that the value of T can be any positive number.

Since the value of T can be any positive number, we cannot determine the exact time it will take for the vehicles to meet. However, we can say that they will meet in less than or equal to 18 hours.

Therefore, the answer to the question "Through how many hours will they meet?" is less than or equal to 18 hours.

Conclusion

The truck and the car will meet in less than or equal to 18 hours. The exact time cannot be determined without additional information about the speeds of the vehicles.

Please let me know if I can help you with anything else.