Question

Известно что Лодка проплывает по озеру 25 километров и 9 километров против течения реки за такое же время за которое она проплывает 56 километр по течению реки Какова скорость лодки в стоячей воде если скорость течения реки равна 2 километра в час

Answer 1

T=s/v, t(по озеру)=25/v; t(против течения)=9/v-2; t(по течению)=56/(v+2); 25/v+9/(v-2)=56(v+2); 25(v^2-4)+9v(v+2)=56v(v-2),22v^2-130v+100=0, D=4225-2200=2025=45^2, v(1)=(65+45)/22=5км/ч; v(2)=(65-45)/22=20/22 - не может быть(меньше течения) ; собственная скорость 5км/ч )))) 

Answer 2

Calculating the Boat's Speed in Still Water

To calculate the speed of the boat in still water, we can use the following formula:

Boat's speed in still water = (Speed downstream + Speed upstream) / 2

Given: - Distance downstream = 56 km - Distance upstream = 9 km - Speed of the river's current = 2 km/h

First, let's calculate the time taken to travel downstream and upstream.

Time taken downstream = Distance downstream / (Boat's speed + River's speed) Time taken upstream = Distance upstream / (Boat's speed - River's speed)

Now, we can use the given information to calculate the boat's speed in still water.

Calculations

1. Time taken downstream: - Distance downstream = 56 km - Boat's speed = x (to be determined) - River's speed = 2 km/h - Using the formula: Time taken downstream = 56 / (x + 2)

2. Time taken upstream: - Distance upstream = 9 km - Boat's speed = x (to be determined) - River's speed = 2 km/h - Using the formula: Time taken upstream = 9 / (x - 2)

Now, we can set up the equation based on the given information and solve for the boat's speed in still water.

Solution

The boat's speed in still water can be calculated using the following equation: 56 / (x + 2) = 9 / (x - 2)

Solving this equation will give us the speed of the boat in still water.

Let's proceed with solving the equation to find the boat's speed in still water.