Question

БЛИЦтурнир. Решите задачи: 1.навстречу друг другу едут два поезда. Скорость одного из них равна а км/ч, что составляет 4/5 скорости другого поезда. Чему равна их скорость сближения? 2.Две лодки плывут по реке навстречу друг другу. Сейчас между ними км. Скорость первой лодки с км ч, а скорость второй-в 3 раза меньше. Какое расстояние будет между лодками через 2 ч, если известно, что до этого времени они не встретятся

Answer 1

1)а    км\ч   -скорость  первого
   5\4а  км\ч  -скорость второго
  а+5\4а=2 1\4а -скорость сближения

Answer 2

Problem 1: Two Trains Approaching Each Other

Two trains are traveling towards each other. The speed of one train is a km/h, which is 4/5 times the speed of the other train. We need to find the speed at which they are approaching each other.

To solve this problem, let's assume the speed of the slower train is x km/h. According to the given information, the speed of the faster train is 4/5 times the speed of the slower train, which can be expressed as (4/5)x km/h.

The relative speed at which the two trains are approaching each other is the sum of their speeds. Therefore, the speed at which they are approaching each other is:

x + (4/5)x = (9/5)x

So, the speed at which the two trains are approaching each other is (9/5)x km/h.

Problem 2: Two Boats Approaching Each Other on a River

Two boats are moving towards each other on a river. The current distance between them is d km. The speed of the first boat is s km/h, and the speed of the second boat is three times slower than the first boat.

To find the distance between the boats after 2 hours, we need to consider the relative speed at which they are approaching each other.

Let's assume the speed of the second boat is x km/h. According to the given information, the speed of the first boat is three times faster than the second boat, which can be expressed as 3x km/h.

The relative speed at which the two boats are approaching each other is the sum of their speeds. Therefore, the relative speed is:

3x + x = 4x

In 2 hours, the distance covered by the boats will be equal to the relative speed multiplied by the time. Therefore, the distance between the boats after 2 hours is:

2 * 4x = 8x

So, the distance between the boats after 2 hours will be 8x km.

Please note that the specific values for a, x, s, and d were not provided in the question, so we cannot provide the exact numerical answers. However, the formulas and methods provided above can be used to solve the problems once the specific values are known.