Question

из двух городов навстречу друг другу выехали две машины, расстояние между городами 800 км. Скорость первой машины 70 км/ч, второй 90 км/ч. Через сколько часов они встретятся? На сколько км первая машина проедет меньше, чем вторая?

Answer 1

Ответ:

5 часов, 100 км

Пошаговое объяснение:

1)70+90=160 (км/ч) - скорость сближения машин

2) 800 : 160 =5 (ч) - через 5 часов они встретятся

3) 70*5=350 (км) - проедет первая машина

4) 90*5=450 (км) - проедет вторая машина

5) 450 - 350 = 100 (км) - на 100 км первая машина проедет меньше

Answer 2

Problem Analysis

Two cars are traveling towards each other from two different cities. The distance between the cities is 800 km. The first car is traveling at a speed of 70 km/h, and the second car is traveling at a speed of 90 km/h. We need to determine how many hours it will take for the cars to meet and the difference in the distance traveled by the first and second cars.

Calculation

To find the time it takes for the cars to meet, we can use the formula:

Time = Distance / Relative Speed

The relative speed of the two cars is the sum of their individual speeds:

Relative Speed = Speed of Car 1 + Speed of Car 2

Let's calculate the time it takes for the cars to meet:

Relative Speed = 70 km/h + 90 km/h = 160 km/h

Time = 800 km / 160 km/h = 5 hours

Therefore, it will take 5 hours for the cars to meet.

To find the difference in the distance traveled by the first and second cars, we can multiply the time it takes for them to meet by their respective speeds:

Distance Traveled by Car 1 = Speed of Car 1 * Time

Distance Traveled by Car 2 = Speed of Car 2 * Time

Let's calculate the difference in the distance traveled:

Distance Traveled by Car 1 = 70 km/h * 5 hours = 350 km

Distance Traveled by Car 2 = 90 km/h * 5 hours = 450 km

Difference = Distance Traveled by Car 2 - Distance Traveled by Car 1

Difference = 450 km - 350 km = 100 km

Therefore, the first car will travel 100 km less than the second car.

Answer

The cars will meet after 5 hours of travel. The first car will travel 100 km less than the second car.