Question

Две девочки одновременно побежали на встречу друг другу по спортивной дорожке , длина которой 420 метров. Когда они встретились,первая пробежала на 60 м больше, чем вторая. С какой скоростью бежала каждая девочка ,если они встретились через 30 секунд?

Answer 1

Длина-420 метров Первая пробежала 240 метров Вторая пробежала 180 метров Если они встретились через 30 секунд то первая 8 м/с, вторая 6 м/с Проверим 8м×30с=240м; 6м×30с=180м; 240м+180м=420м

Answer 2

Problem Analysis

We are given that two girls are running towards each other on a sports track that is 420 meters long. When they meet, the first girl has run 60 meters more than the second girl. We need to find the speed at which each girl is running, given that they meet after 30 seconds.

Solution

Let's assume that the speed of the first girl is x meters per second and the speed of the second girl is y meters per second.

We know that the distance traveled by each girl is equal to their speed multiplied by the time taken. Therefore, we can write the following equations:

For the first girl: Distance = Speed * Time 420 = x * 30

For the second girl: Distance = Speed * Time 420 = y * 30

We are also given that the first girl runs 60 meters more than the second girl. Therefore, we can write another equation:

x = y + 60

Now we have a system of three equations that we can solve to find the values of x and y.

Solving the Equations

Let's solve the system of equations using substitution or elimination method.

From the equation x = y + 60, we can substitute the value of x in the first equation:

420 = (y + 60) * 30

Simplifying the equation:

420 = 30y + 1800

Rearranging the equation:

30y = 420 - 1800 30y = -1380 y = -1380 / 30 y = -46

Substituting the value of y in the equation x = y + 60:

x = -46 + 60 x = 14

Therefore, the speed of the first girl is 14 meters per second and the speed of the second girl is -46 meters per second.

Answer

The first girl is running at a speed of 14 meters per second and the second girl is running at a speed of -46 meters per second.