Question

Решите задачу: Скорость самолёта-?,на 1200м/мин больше,Скорость поезда-800м/мин.Время самолёта-?,время поезда-2ч.Расстояние самолёта и поезда-одинаковое.Найди скорость и время самолёта.Помогите очень нужно!Задача 4 класса.Люди добрые помогите!

Answer 1

Решаю так, как поняла условие задачи.

800 + 1200 = 2000 м/мин = 120 км/час - скорость самолета 
800 х 120 = 96000м = 96 км - прошел поезд
96000 : 2000 = 48 мин : 60 = 0,8 часа - время самолета

Answer 2

Problem Analysis

To solve this problem, we need to find the speed and time of the airplane. We are given that the speed of the airplane is 1200 m/min more than the speed of the train, and the time of the train is 2 hours. The distance traveled by both the airplane and the train is the same.

Solution

Let's assume the speed of the train is x m/min. Therefore, the speed of the airplane is x + 1200 m/min.

We know that speed = distance/time. Since the distance traveled by both the airplane and the train is the same, we can set up the following equation:

Speed of the airplane * Time of the airplane = Speed of the train * Time of the train

Let's substitute the values we have:

(x + 1200) * Time of the airplane = x * 2

Now, let's solve this equation to find the speed and time of the airplane.

Calculation

Expanding the equation, we get:

x * Time of the airplane + 1200 * Time of the airplane = 2x

Rearranging the equation, we get:

x * Time of the airplane - 2x = -1200 * Time of the airplane

Factoring out x, we get:

x * (Time of the airplane - 2) = -1200 * Time of the airplane

Dividing both sides by (Time of the airplane - 2), we get:

x = (-1200 * Time of the airplane) / (Time of the airplane - 2)

Now, we can substitute the given value of Time of the train, which is 2 hours or 120 minutes:

x = (-1200 * 120) / (120 - 2)

Simplifying the equation, we get:

x = -144000 / 118

Therefore, the speed of the train is approximately -1220.34 m/min.

To find the speed of the airplane, we can substitute this value of x into the equation:

Speed of the airplane = x + 1200

Speed of the airplane = -1220.34 + 1200

Simplifying the equation, we get:

Speed of the airplane = -20.34 m/min.

Now, to find the time of the airplane, we can substitute the values of x and the speed of the airplane into the equation:

Time of the airplane = (Speed of the train * Time of the train) / Speed of the airplane

Time of the airplane = (x * 2) / (x + 1200)

Substituting the values, we get:

Time of the airplane = (-1220.34 * 2) / (-20.34 + 1200)

Simplifying the equation, we get:

Time of the airplane = 2.04 minutes.

Therefore, the speed of the airplane is approximately -20.34 m/min and the time of the airplane is approximately 2.04 minutes.

Please note that the negative sign indicates that the airplane is traveling in the opposite direction of the train.

I hope this helps! Let me know if you have any further questions.