Question

Собственная скорость моторной лодки 8км/ч.Скорость течение реки одна целая 2/5 км/ч.Лодка шла 2 ч против течение реки и 2 ч по течению реки. Кокой путь прошла моторная лодка за эти 4 часа?​

Answer 1

Ответ:

1) 8 - 1 2/5 = 40/5 - 7/5 = 33/5 = 6 3/5 км/ч - скорость против течения,

2) 8 + 1 2/5 = 9 2/5 км/ч - скорость по течению,

3) 6 3/5 * 2 = 13 1/5 км - расстояние против течени,

4) 9 2/5 * 2 = 18 4/5 км - расст. по течению,

5) 13 1/5 + 18 4/5 = 32 км.

Answer 2

Calculation of the Distance Traveled by the Motorboat

To calculate the distance traveled by the motorboat, we need to consider the speed of the boat and the speed of the river's current.

Given: - Speed of the motorboat: 8 km/h - Speed of the river's current: 2/5 km/h

We know that the boat traveled against the current for 2 hours and then traveled with the current for another 2 hours.

To calculate the distance traveled against the current, we can use the formula:

Distance = Speed × Time

Distance against the current = (Speed of the motorboat - Speed of the river's current) × Time

Substituting the given values:

Distance against the current = (8 km/h - 2/5 km/h) × 2 hours

Simplifying the expression:

Distance against the current = (40/5 - 2/5) × 2 km

Distance against the current = (38/5) × 2 km

Distance against the current = 76/5 km

To calculate the distance traveled with the current, we can use the same formula:

Distance with the current = (Speed of the motorboat + Speed of the river's current) × Time

Substituting the given values:

Distance with the current = (8 km/h + 2/5 km/h) × 2 hours

Simplifying the expression:

Distance with the current = (40/5 + 2/5) × 2 km

Distance with the current = (42/5) × 2 km

Distance with the current = 84/5 km

Finally, to calculate the total distance traveled by the motorboat in 4 hours, we add the distances traveled against and with the current:

Total distance = Distance against the current + Distance with the current

Total distance = 76/5 km + 84/5 km

Total distance = (76 + 84)/5 km

Total distance = 160/5 km

Total distance = 32 km

Therefore, the motorboat traveled a total distance of 32 kilometers in 4 hours.

Note: The search results provided by You.com did not contain relevant information for this specific calculation. The calculation was performed based on the given information and the formula for calculating distance using speed and time.