Question

Помогите решить задачу! 7 класс!Из пункта А в пункт В со скоростью 17км/ч выехал автомобиль, а через 2 часа навстречу ему из пункта В вышел пешеход со скоростью 6 км/ч. на каком расстоянии от пункта А произошла их встреча, если расстояние между пунктами А и В равно 103 км?

Answer 1

17 х 2 = 34 км - проехал автомобиль до старта пешехода
103-34=69 км - расстояние между пешеходом и автомобилем в момент старта пешехода
Встреча произошла через 3 часа:
69-17=52-17=35-17=18
6+6+6=18
... в 18 километрах не доезжая пункт В, то есть в 103-18=85 км от пункта А

Answer 2

Ко времени выхода пешехода из В велосипедист проехал:
                                                           S₁ = v₁t₁ = 17 * 2 = 34 (км) 
Следовательно, расстояние между ними в этот момент было:
                                                           S₂ = S - S₁ = 103 - 34 = 69 (км)
Скорость сближения велосипедиста и пешехода:
                                                             v = v₁ + v₂ = 17 + 6 = 23 (км/ч)

Время до встречи: t = S₂/v = 69 : 23 = 3 (ч)

Велосипедист ехал до встречи: t₂ = t₁ + t = 2 + 3 = 5 (ч)

Расстояние от пункта А до места встречи: S₃ = v₁ * t₂ = 17 * 5 = 85 (км)

Answer 3

Problem Analysis

To solve this problem, we need to find the distance from point A where the car and pedestrian meet. We are given that the car travels at a speed of 17 km/h and the pedestrian walks at a speed of 6 km/h. The distance between points A and B is 103 km.

Solution

Let's break down the problem step by step:

1. The car travels at a speed of 17 km/h for 2 hours. Therefore, the car covers a distance of 17 km/h * 2 h = 34 km from point A.

2. After 2 hours, the pedestrian starts walking from point B towards point A at a speed of 6 km/h.

3. To find the distance from point A where the car and pedestrian meet, we need to determine the time it takes for the pedestrian to cover the remaining distance between the car and point B.

4. Let's assume the distance from point A where the car and pedestrian meet is x km. The remaining distance from this point to point B is (103 km - x km).

5. The time it takes for the pedestrian to cover the remaining distance is given by the formula: time = distance / speed.

6. The time it takes for the pedestrian to cover the remaining distance is: (103 km - x km) / 6 km/h.

7. Since the car and pedestrian meet after 2 hours, the total time taken by the pedestrian is: 2 hours + (103 km - x km) / 6 km/h.

8. The total distance covered by the pedestrian is: (103 km - x km) + 34 km.

9. Since the car and pedestrian meet at the same point, the total distance covered by the car is also: (103 km - x km) + 34 km.

10. We can set up an equation to solve for x: - Distance covered by the car = Distance covered by the pedestrian - (103 km - x km) + 34 km = (103 km - x km) + 34 km

11. Simplifying the equation, we get: - 103 km - x km + 34 km = 103 km - x km + 34 km - 137 km - x km = 137 km - x km

12. The x term cancels out on both sides of the equation, leaving us with: - 137 km = 137 km

13. This equation is true for any value of x. Therefore, the distance from point A where the car and pedestrian meet can be any value between 0 km and 103 km.

Answer

The distance from point A where the car and pedestrian meet can be any value between 0 km and 103 km.

Please let me know if you need any further assistance!