Question

Составь уравнение и реши задачу. Из посёлка одновременно в противоположных направлениях вышли два пешехода.Через 3ч расстояние между ними было равно 27км. Один из них шёл со скоростью 4км/ч. С какой скоростью шёл второй пешеход

Answer 1

Problem Analysis

We are given that two pedestrians started walking in opposite directions from a village. After 3 hours, the distance between them was 27 km. We also know that one of the pedestrians was walking at a speed of 4 km/h. We need to find the speed at which the second pedestrian was walking.

Solution

Let's assume the speed of the second pedestrian is x km/h.

Since the pedestrians are walking in opposite directions, their speeds should be added to find the relative speed between them. The relative speed is the rate at which the distance between them is changing.

The relative speed can be calculated as the sum of their individual speeds:

Relative speed = Speed of pedestrian 1 + Speed of pedestrian 2

In this case, the relative speed is equal to the distance between them divided by the time taken:

Relative speed = Distance / Time

Substituting the given values, we have:

Relative speed = 27 km / 3 hours

Simplifying, we get:

Relative speed = 9 km/h

Since the relative speed is the sum of the speeds of the two pedestrians, we can write the equation:

4 km/h + x km/h = 9 km/h

To find the speed of the second pedestrian, we can solve this equation for x.

Solving the Equation

To solve the equation, we can subtract 4 km/h from both sides:

x km/h = 9 km/h - 4 km/h

Simplifying, we get:

x km/h = 5 km/h

Therefore, the second pedestrian was walking at a speed of 5 km/h.

Conclusion

The second pedestrian was walking at a speed of 5 km/h.