Question

Два самолёта вылетели одновременно из Москвы в одном и том же направлении: один-со скоростью 350 км/ч, а другой-со скоростью 280 км/ч. Через два часа первый уменьшил скорость до 230 км/ч. На каком расстоянии от Москвы второй самолёт догонит первый?

Answer 1

350-280=70км/час скорость, в которой первый удалялся от второго сначала
70*2=140км расстояние между ними, когда первый уменьшил скорость
2802-230=50км/час скорость, с которой второй догоняет первый
140:50=2.8 часа догонит
2+2,8=4,8часа был в пути второй самолет
280*4,8=1344км от Москвы

Answer 2

Problem Analysis

We have two planes that took off simultaneously from Moscow in the same direction. One plane is flying at a speed of 350 km/h, while the other is flying at a speed of 280 km/h. After two hours, the first plane reduces its speed to 230 km/h. We need to determine at what distance from Moscow the second plane will catch up to the first plane.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's calculate the distance traveled by each plane after two hours:

- The first plane travels at a speed of 350 km/h for two hours, so its distance is 350 km/h × 2 h = 700 km. - The second plane travels at a speed of 280 km/h for two hours, so its distance is 280 km/h × 2 h = 560 km.

Now, we need to determine the time it takes for the second plane to catch up to the first plane. Since the first plane is now flying at a reduced speed of 230 km/h, we can calculate the time it takes for the second plane to cover the remaining distance between them.

Let's denote the distance between the two planes as d. The time it takes for the second plane to catch up to the first plane is given by the equation:

d = (350 km/h - 230 km/h) × t

Simplifying the equation, we get:

d = 120 km/h × t

To find the value of t, we can divide the distance traveled by the second plane by its speed:

t = d / 120 km/h

Substituting the value of d with the distance traveled by the first plane after two hours (700 km - 560 km = 140 km), we get:

t = 140 km / 120 km/h

Simplifying the equation, we find:

t ≈ 1.17 hours

Now, we can calculate the distance from Moscow where the second plane catches up to the first plane. We can use the formula:

distance = speed × time

Substituting the values, we get:

distance = 280 km/h × 1.17 h ≈ 327.6 km

Therefore, the second plane will catch up to the first plane at a distance of approximately 327.6 km from Moscow.

Answer

The second plane will catch up to the first plane at a distance of approximately 327.6 km from Moscow.