Question

Расстояние между пристанями 24 км. лодка проплыла от одной пристани до другой и вернулась обратно, затратив на весь путь 5 часов. найдите собственную скорость лодки, если скорость течения реки 2 км/ч.

Answer 1

х-собственная скорость

х+2-по течению

х-2-против течения

24*2=48-проплыла всего

по условию 5 часов затрачено

(х+2+х-2)*5=48

2х*5=48

х=4,8

 

Answer 2

Calculating the Boat's Speed

To find the boat's speed, we can use the formula: speed = distance / time.

Given: - Distance between piers = 24 km - Boat's round trip time = 5 hours - River's flow speed = 2 km/h

We can calculate the boat's speed using the formula: speed = distance / time

The boat's speed is given by: speed = 24 km / 5 hours = 4.8 km/h.

However, we need to consider the effect of the river's flow on the boat's speed. The boat's speed in still water is the average of its speed upstream and downstream.

Adjusting for River Flow

The boat's speed in still water can be calculated using the formula: boat's speed in still water = (speed upstream + speed downstream) / 2.

The boat's speed upstream is given by: speed upstream = (boat's speed - river's flow speed).

The boat's speed downstream is given by: speed downstream = (boat's speed + river's flow speed).

Substituting the given values: - Speed upstream = (4.8 km/h - 2 km/h) = 2.8 km/h - Speed downstream = (4.8 km/h + 2 km/h) = 6.8 km/h

The boat's speed in still water is: boat's speed in still water = (2.8 km/h + 6.8 km/h) / 2 = 4.8 km/h.

Therefore, the boat's speed in still water is 4.8 km/h.