Question

Катер проплывает 8 км против течения и еще 30 км по течению за то же время, за которое плот может проплыть по этой реке 4 км. скорость катера в стоячей воде равна 18 км/ч. найдите скорость течения реки.

Answer 1

Допустим,что  x=скорость течения реки.следовательно скорость  течение против реки=V собств - V течения реки=18-x...,а скорость  течения по реке= V  собств + V течения реки= 18 +x

Теперь  мы можем составить  уравнение:

8/18-x + 30/18+x =4/x

Решив уравнение,получим.что x=2,т.е скорость течения реки=2

Answer 2

Calculating the River's Current Speed

To find the speed of the river's current, we can use the following formula: Speed of boat in still water = (Speed downstream + Speed upstream) / 2 Speed of current = (Speed downstream - Speed upstream) / 2

Given: - Distance upstream = 8 km - Distance downstream = 30 km - Boat's speed in still water = 18 km/h - Time taken for both distances is the same - Time taken to travel 4 km downstream = Time taken to travel 8 km upstream

Calculating Speed Downstream and Upstream

Let's calculate the boat's speed downstream and upstream using the given information.

Speed downstream: - Time taken to travel 30 km downstream = 30 km / (18 km/h + Speed of current) - Time taken to travel 8 km upstream = 8 km / (18 km/h - Speed of current)

Speed upstream: - Time taken to travel 30 km downstream = 30 km / (18 km/h - Speed of current) - Time taken to travel 8 km upstream = 8 km / (18 km/h + Speed of current)

Solving for the Speed of the River's Current

We can now solve for the speed of the river's current using the calculated speeds downstream and upstream.

Speed of boat in still water = (Speed downstream + Speed upstream) / 2 Speed of current = (Speed downstream - Speed upstream) / 2

Let's calculate the speed of the river's current using the above formulas.