Question

Собственная скорость теплохода в 9 раз больше скорости течения реки Найдите собственную скорость теплохода и скорость течения реки если теплоход прошёл путь в 138 км двигаясь 3 часа по течению реки и 2 часа против течения реки?

Answer 1

Ответ:

( 9х + х ) * 1,25 = 45

 10х = 45 : 1,25

 10х = 36

  х = 36 : 10

  х = 3,6 (км/ч) - течение реки.

  9 * 3,6 = 32,4 (км/ч) - скорость теплохода.

32,4 - 3,6 = 28,8 (км/ч) - скорость теплохода против течения реки.

Answer 2

Ответ:

Пусть х км/ч - скорость течения реки, тогда 9х км/ч - собственная скорость теплохода, (9х + х) км/ч - скорость теплохода по течению реки,1 ч 15 мин = 1,25 ч.

Уравнение: (9х + х) * 1,25 = 45

10х = 45 : 1,25

10х = 36

х = 36 : 10

х = 3,6 (км/ч) - скорость течения реки

9 * 3,6 = 32,4 (км/ч) - собственная скорость теплохода

32,4 - 3,6 = 28,8 (км/ч) - скорость теплохода против течения реки

Ответ: 28,8 км/ч.

Answer 3

Calculation of the Ship's Speed and River Current Speed

To find the ship's speed and the river current speed, we can use the given information about the distance traveled and the time taken in different directions.

Let's denote the ship's speed as S and the river current speed as C.

1. When the ship is moving with the current, the effective speed is the sum of the ship's speed and the river current speed: - Effective speed = Ship's speed + River current speed = S + C

2. When the ship is moving against the current, the effective speed is the difference between the ship's speed and the river current speed: - Effective speed = Ship's speed - River current speed = S - C

We are given the following information: - The ship traveled a distance of 138 km. - The ship traveled for 3 hours with the current. - The ship traveled for 2 hours against the current.

Using this information, we can set up the following equations:

1. When the ship is moving with the current: - Distance = Speed × Time - 138 km = (S + C) × 3 hours

2. When the ship is moving against the current: - Distance = Speed × Time - 138 km = (S - C) × 2 hours

Let's solve these equations to find the ship's speed (S) and the river current speed (C).

Solving the Equations

1. When the ship is moving with the current: - 138 km = (S + C) × 3 hours - Dividing both sides by 3: 46 km/h = S + C 2. When the ship is moving against the current: - 138 km = (S - C) × 2 hours - Dividing both sides by 2: 69 km/h = S - C Now we have a system of equations: - S + C = 46 km/h - S - C = 69 km/h Adding equation and equation together, we can eliminate the variable C: - (S + C) + (S - C) = 46 km/h + 69 km/h - 2S = 115 km/h

Dividing both sides by 2, we find the ship's speed (S): - S = 57.5 km/h

Substituting the value of S into equation we can find the river current speed (C): - 57.5 km/h + C = 46 km/h - C = 46 km/h - 57.5 km/h - C = -11.5 km/h

Answer

Therefore, the ship's speed is 57.5 km/h and the river current speed is -11.5 km/h.

Please note that the negative sign for the river current speed indicates that the current is flowing in the opposite direction of the ship's movement.