Question

Из двух деревень,находящихся на расстоянии 27 км,одновременно навстречу друг другу вышли два пешехода.Через 3 ч они встретились.Один пешеход шел со скоростью 5 км/ч.С какой скоростью шел другой пешеход?Реши задачу двумя способами.

Answer 1

                         1 способ

1) 27:3=9 км в час-общая скорость
2) 9-5=4 км в час

                         2 способ

1) 5*3=15 км-прошёл1-ый пешеход
2) 27-15=12 км-прошёл 2-ой пешеход
3) 12:3=4 км в час
Ответ: 2-ой пешеход шёл со скоростью 4 км в час

Answer 2

Problem Statement

Из двух деревень, находящихся на расстоянии 27 км, одновременно навстречу друг другу вышли два пешехода. Через 3 часа они встретились. Один пешеход шел со скоростью 5 км/ч. С какой скоростью шел другой пешеход?

Solution 1: Using Relative Speed

To solve this problem, we can use the concept of relative speed. The relative speed of two objects moving towards each other is the sum of their individual speeds.

The formula for relative speed is: Relative Speed = Speed of Object 1 + Speed of Object 2

In this case, the relative speed is equal to the distance between the two villages divided by the time taken to meet.

Given: - Distance = 27 km - Time taken to meet = 3 hours - Speed of one pedestrian = 5 km/h

Using the relative speed formula, we can calculate the speed of the other pedestrian.

Solution 2: Using Time, Distance, and Speed Formula

Another way to solve this problem is by using the time, distance, and speed formula: Distance = Speed × Time

We can use this formula to find the speed of the second pedestrian.

Solution

1. Using Relative Speed: - Relative Speed = Distance / Time - Relative Speed = 27 km / 3 h - Relative Speed = 9 km/h Since the total relative speed is the sum of the speeds of both pedestrians, we can find the speed of the second pedestrian by subtracting the speed of the first pedestrian from the relative speed. - Speed of the second pedestrian = Relative Speed - Speed of the first pedestrian - Speed of the second pedestrian = 9 km/h - 5 km/h - Speed of the second pedestrian = 4 km/h

2. Using Time, Distance, and Speed Formula: - Let the speed of the second pedestrian be represented by x km/h. - Distance = Speed × Time - For the first pedestrian: 5 km/h × 3 h = 15 km - For the second pedestrian: x km/h × 3 h = 3x km

Since the total distance is 27 km, we can write the equation: - 15 km + 3x km = 27 km - 3x km = 27 km - 15 km - 3x km = 12 km - x = 4 km/h

Conclusion

The second pedestrian was walking with a speed of 4 km/h. This result is consistent with the calculation using the relative speed method.