Question

60 Баллов!!! Катер прошёл по течению реки расстояние межу двумя пристанями за 6,5 часа со скоростью 300м/мин .Сколько времени потребуется катеру на обратный путь ,если скорость течения 2,5км/ч?

Answer 1

Найдем расстояние между пристанями:
300 м/мин=18 км/ч
S=Vt=18*6,5=117 км
Скорость против течения - 18-2.5-2.5=13 км/ч
На обратный путь потребуется 117:13=9 ч.

Answer 2

Problem Analysis

We are given that a boat traveled a certain distance between two piers in a river in 6.5 hours at a speed of 300 m/min. We need to find out how long it will take for the boat to return if the speed of the current is 2.5 km/h.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's calculate the distance traveled by the boat in the given time: - Speed of the boat = 300 m/min - Time taken = 6.5 hours = 6.5 * 60 minutes = 390 minutes - Distance = speed * time = 300 m/min * 390 min = 117,000 meters

Now, let's calculate the time it will take for the boat to return with the current: - Speed of the boat = 300 m/min - Speed of the current = 2.5 km/h = 2.5 * 1000 m / 60 min = 41.67 m/min (approx.) - Total speed of the boat with the current = speed of the boat + speed of the current = 300 m/min + 41.67 m/min = 341.67 m/min (approx.) - Distance to be traveled = 117,000 meters (same as the distance traveled earlier) - Time = distance / speed = 117,000 meters / 341.67 m/min ≈ 342.2 minutes

Therefore, it will take approximately 342.2 minutes for the boat to return with the current.

Answer

The boat will take approximately 342.2 minutes to return with the current.