Question

Лодка догоняет плот, который находится от неё на расстоянии 2км вниз по течению реки.Собственная скорость лодки 5 км/ч. Через какое время лодка догонит плот, если скорость течения реки 3,4 км/4?

Answer 1

2км:5км/час=0,4 часа =24 минуты

Скорость течения реки нет смысла прибавлять, так как плот так же плыл со скоростью реки

 

Answer 2

5+3,4=8,4км/ч скорость лодки
3,4км/ч скорость плота
Когда лодка догонит плот она пройдет расстояние на 2км больше плота
8,4х=3,4х+2
8,4х-3,4х=2
5х=2
Х=2/5 часа т.е. 24 минуты
Ответ:24 минуты

Answer 3

Problem Analysis

We are given the following information: - The boat is chasing a raft that is 2 km downstream from it. - The boat's speed is 5 km/h. - The river's current speed is 3.4 km/h.

We need to determine how long it will take for the boat to catch up to the raft.

Solution

To solve this problem, we can use the concept of relative velocity. The boat's speed relative to the river is the difference between the boat's speed and the river's current speed. In this case, the boat's speed relative to the river is 5 km/h - 3.4 km/h = 1.6 km/h.

Since the boat is chasing the raft downstream, the relative velocity between the boat and the raft is the sum of their individual velocities. Therefore, the relative velocity between the boat and the raft is 1.6 km/h + 3.4 km/h = 5 km/h.

To find the time it takes for the boat to catch up to the raft, we can use the formula:

time = distance / speed

In this case, the distance between the boat and the raft is 2 km, and the relative velocity between them is 5 km/h. Plugging these values into the formula, we get:

time = 2 km / 5 km/h

Calculating this, we find that it will take the boat 0.4 hours to catch up to the raft.

Answer

The boat will catch up to the raft in 0.4 hours.