Question

Срочно!!!Човен плив 13 годин за течією річки тим самим шляхом що і 15 годин проти течії. Швидкість човна становить 70 км/год. Знайдіть швидкість км/год стоячої води.

Answer 1

Відповідь:

Покрокове пояснення:

Answer 2

Problem Analysis

We are given that a boat travels downstream for 13 hours along a river at a speed of 70 km/h, and then travels upstream for 15 hours along the same path at an unknown speed. We need to find the speed of the standing water.

Solution

Let's assume the speed of the standing water is x km/h.

When the boat is traveling downstream, its effective speed is the sum of its own speed and the speed of the standing water. Therefore, the effective speed downstream is 70 + x km/h.

When the boat is traveling upstream, its effective speed is the difference between its own speed and the speed of the standing water. Therefore, the effective speed upstream is 70 - x km/h.

We are given that the boat travels downstream for 13 hours and upstream for 15 hours along the same path. Since the distance traveled is the same in both cases, we can set up the following equation:

Distance downstream = Distance upstream

Using the formula distance = speed × time, we can write:

(70 + x) × 13 = (70 - x) × 15

Simplifying the equation:

910 + 13x = 1050 - 15x

Combining like terms:

28x = 140

Dividing both sides by 28:

x = 5

Therefore, the speed of the standing water is 5 km/h.

Conclusion

The speed of the standing water is 5 km/h.