Question

Реши задачу разными способами. расстояние между поселками равно 39 км. из одного поселка вышел первый пешеход со скоростью 4 км/ч,а из другого поселка через 3 часа навстречу ему — второй пешеход со скоростью 5 км/ч. сколько времени будет идти второй пешеход до встречи с первым?

Answer 1

1.4км/ч*3ч=12 км(пройдёт первый до выхода второго)
2.39 км-12 км=27 км( остоток пути между посёлками)
3.4 км/ч+5км/ч=9 км/ч (скорость сближения пешеходов)
4. 27 км/9 км/ч=3 ч (время второго пешехода до встречи)
ответ: 3 часа будет идти второй до встречи с первым.

Answer 2

4*3=12км (1 пеш до 2 пеш)
38-12=27км (осталось между поселками)
4+5=9ч (скорсоть встречи пеш)
27/9=3 ч (2 пеш до встречи)

Answer 3

Problem Statement

We have two pedestrians walking towards each other from two different villages. The distance between the villages is 39 km. The first pedestrian starts walking at a speed of 4 km/h, and the second pedestrian starts walking 3 hours later towards the first pedestrian at a speed of 5 km/h. We need to find out how much time the second pedestrian will walk before meeting the first pedestrian.

Solution 1: Using Relative Speed

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

The time taken for the second pedestrian to meet the first pedestrian can be calculated using the formula: Time = Distance / Relative Speed

The relative speed of the two pedestrians is the sum of their individual speeds.

Using this formula, we can calculate the time taken for the second pedestrian to meet the first pedestrian.

Calculations: - Relative Speed = 4 km/h + 5 km/h = 9 km/h - Time = 39 km / 9 km/h = 4.33 hours

Answer: The second pedestrian will walk for approximately 4.33 hours before meeting the first pedestrian.

Solution 2: Using Time Difference

Another way to solve this problem is by considering the time difference between the two pedestrians. Since the second pedestrian starts walking 3 hours later, we can calculate the time it takes for the first pedestrian to cover the distance in those 3 hours, and then find the remaining time for the second pedestrian to cover the remaining distance.

Calculations: - Distance covered by the first pedestrian in 3 hours = Speed * Time = 4 km/h * 3 h = 12 km - Remaining distance = Total distance - Distance covered by the first pedestrian = 39 km - 12 km = 27 km - Time taken by the second pedestrian to cover the remaining distance = Distance / Speed = 27 km / 5 km/h = 5.4 hours

Answer: The second pedestrian will walk for approximately 5.4 hours before meeting the first pedestrian.

Both methods yield similar results, and either approach can be used to solve the problem.