Question

Решите пожалуйста!!! 21. Дорога между посёлками состоит из спуска и подъёма. Селянин про- шёл весь путь за 6 часов, причём подъём занял 2 часа. Найдите скорость селянина на спуске (в км/ч), если длина всей дороги 26 км и скорость его на спуске больше скорости на подъёме на 2 км/ч.

Answer 1

Пусть Х км/ч - скорость на подъеме ,
тогда ( Х+2) км/ч - скорость на спуске
Известно , что подъем занял 2 ч , значит 2х - длина подъема
а спуск занял 6 ч -2 ч = 4 ч , значит 4(Х+2) - длина спуска
Известно, что весь путь 26 км
Составим уравнение:
2х+4(Х+2)=26
2х+4х+8=26
6х=18
Х=3км/ч - скорость на подъеме
Х+2=3+2= 5 км/ч - скорость на спуске

Answer 2

Solution:

To solve this problem, we can use the formula:

average speed = total distance / total time

First, let's find the speed of the villager on the ascent and then use the given information to find the speed on the descent.

Given: - Total distance = 26 km - Time for ascent = 2 hours - Total time = 6 hours - Speed on descent > speed on ascent by 2 km/h

Speed on the Ascent:

The time taken for the ascent is 2 hours, and the distance is unknown. We can use the formula:

speed = distance / time

So, the speed on the ascent is: ``` speed_ascent = distance_ascent / time_ascent = ? / 2 ```

Speed on the Descent:

The time taken for the descent is 6 - 2 = 4 hours. We can use the formula:

speed = distance / time

So, the speed on the descent is: ``` speed_descent = distance_descent / time_descent = ? / 4 ```

Using the Given Information:

We know that the speed on the descent is greater than the speed on the ascent by 2 km/h. Therefore: ``` speed_descent = speed_ascent + 2 ```

Calculating the Speed on the Ascent:

We can use the formula for average speed to find the distance on the ascent: ``` average speed = total distance / total time speed_ascent = distance_ascent / 2 distance_ascent = speed_ascent * 2 ```

Substituting and Solving:

Substitute the value of distance_ascent into the equation for speed_descent: ``` speed_descent = (speed_ascent * 2) / 4 speed_descent = speed_ascent / 2 ```

Now, substitute the value of speed_descent from the given information: ``` speed_ascent / 2 = speed_ascent + 2 speed_ascent = 2 * (speed_ascent + 2) speed_ascent = 2 * speed_ascent + 4 speed_ascent - 2 * speed_ascent = 4 - speed_ascent = 4 speed_ascent = -4 ```

Conclusion:

It seems there might be an error in the given problem. The calculated speed on the ascent is negative, which is not possible. Please double-check the given information and the problem statement for accuracy.