Question

Из пункта А в пункт В, расстояние между которыми 680 км,вышел поезд со скорость 80 км/ч, Через полчаса навстречу ему из пункта В вышел другой поезд с той же скоростью, Через сколько времени он встретит 1 поезд...Решите всё с ответом

Answer 1

80*0,5=40км проехал первый поезд до выхода второго
680-40=640км расстояние между ними в момент выхода второго поезда
80+80=160км/час скорость сближения
640:160=4часа через 4 часа второй встретит пкрвый

Answer 2

680-80*0,5=680-40=640км ехали навстречу оба
80+80=160км/ч-скорость сближения
640/160=4ч-  Через сколько времени после выхода 2го поезда он встретит 1 поезд

Answer 3

Problem Analysis

We are given that there are two points, A and B, with a distance of 680 km between them. A train leaves point A with a speed of 80 km/h. After half an hour, another train leaves point B towards point A with the same speed. We need to determine how long it will take for the two trains to meet.

Solution

Let's break down the problem step by step:

1. The first train leaves point A with a speed of 80 km/h. After half an hour, it will have traveled a distance of 40 km (0.5 hours * 80 km/h).

2. The second train leaves point B towards point A with the same speed of 80 km/h. Since the two trains are moving towards each other, their combined speed is 160 km/h (80 km/h + 80 km/h).

3. The total distance between the two trains is 680 km, and after the first train has traveled 40 km, the remaining distance is 640 km (680 km - 40 km).

4. To find the time it takes for the two trains to meet, we can use the formula: time = distance / speed. Plugging in the values, we get: time = 640 km / 160 km/h = 4 hours.

Therefore, the two trains will meet after 4 hours.

Answer

The two trains will meet after 4 hours.

Explanation

The first train leaves point A and travels a distance of 40 km in half an hour. The second train leaves point B towards point A with the same speed. The two trains will meet when the remaining distance between them is 640 km. Since the combined speed of the two trains is 160 km/h, they will meet after 4 hours.