Question

Моторная лодка прошла путь от A до B по течению реки за 3 часа,а обратный путь за 4,5 часа. Найдите скорость течения реки, если известно, что скорость лодки в стоячей воде 25 км/ч.​

Answer 1

Ответ:

5 км/ч

Пошаговое объяснение:

Прикрепил фото смотреть сколько хотите

Answer 2

Calculating the River Current Speed

To calculate the speed of the river current, we can use the formula: speed = distance / time

The speed of the boat in still water is given as 25 km/h. Let's denote the speed of the river current as c.

Downstream Journey

During the downstream journey, the boat's speed is the sum of its speed in still water and the speed of the current, so the effective speed is 25 + c.

Given that the boat took 3 hours for the downstream journey, we can use the formula: 25 + c = distance / 3

Upstream Journey

During the upstream journey, the boat's speed is the difference between its speed in still water and the speed of the current, so the effective speed is 25 - c.

Given that the boat took 4.5 hours for the upstream journey, we can use the formula: 25 - c = distance / 4.5

Solving for the River Current Speed

We can solve these two equations to find the speed of the river current.

First, we can express the distance in terms of speed and time: distance = speed * time

Substituting the expressions for distance from the two equations above, we get: distance = (25 + c) * 3 distance = (25 - c) * 4.5

Equating the two expressions for distance, we get: (25 + c) * 3 = (25 - c) * 4.5

Solving for c: (25 + c) * 3 = (25 - c) * 4.5 75 + 3c = 112.5 - 4.5c 7.5c = 37.5 c = 5

Conclusion

Therefore, the speed of the river current is 5 km/h.