Question

СРОЧНО!!! .Мотоная лодка по течению реки шла 2,5ч а против течения 1,8ч. При этом расстояние, которая преодолела лодка по течению на 17 км больше за расстояние пройденное против течения реки. Найди скорость лодки если скорость течения реки 2км ч. Уровнением​

Answer 1

Скорость катера плывущего по реке равна 20,4+2,5=22,9 км/ч. Значит по течению реки он прошел 22,9*1,5=34,35 км.
Скорость катера плывущего против течения реки 20,4-2,5=17,9 км/ч. Значит против течения он прошел 17,9*1,8=32,22 км.
Весь путь катера составил 34,35+32,22=66,57 км

Answer 2

Ответ:

(14×х)

(14-х)

(14×Х)×3

(14-х)×1

Уровнение:

(14+х)×3-(14-х)×1=40

42+3х-14+Х=40

4х+28=40

4х=12х=3км/ч

Проверяем:

(17×3-11×1)=40

Answer 3

Problem Analysis

We are given that a motorboat traveled downstream for 2.5 hours and upstream for 1.8 hours. The distance covered by the boat downstream is 17 km more than the distance covered upstream. The speed of the river current is given as 2 km/h. We need to find the speed of the boat.

Solution

Let's assume the speed of the boat in still water is x km/h.

When the boat is traveling downstream, it gets a boost from the river current, so its effective speed is the sum of its own speed and the speed of the current. Therefore, the effective speed downstream is (x + 2) km/h.

Similarly, when the boat is traveling upstream, it has to overcome the resistance of the river current, so its effective speed is the difference between its own speed and the speed of the current. Therefore, the effective speed upstream is (x - 2) km/h.

We are given that the boat traveled downstream for 2.5 hours and upstream for 1.8 hours. Let's use the formula distance = speed × time to calculate the distances covered in each direction.

The distance covered downstream is (x + 2) × 2.5 km.

The distance covered upstream is (x - 2) × 1.8 km.

According to the problem statement, the distance covered downstream is 17 km more than the distance covered upstream. Therefore, we can write the equation:

(x + 2) × 2.5 = (x - 2) × 1.8 + 17

Now, let's solve this equation to find the value of x, which represents the speed of the boat in still water.

Solving the Equation

Expanding the equation, we get:

2.5x + 5 = 1.8x - 3.6 + 17

Combining like terms, we have:

2.5x - 1.8x = 17 - 5 + 3.6

Simplifying further, we get:

0.7x = 15.6

Dividing both sides of the equation by 0.7, we find:

x = 15.6 / 0.7

Evaluating the expression, we get:

x ≈ 22.29

Therefore, the speed of the boat in still water is approximately 22.29 km/h.

Answer

The speed of the boat is approximately 22.29 km/h.