Question

Моторная лодка, двигаясь против течения реки, за 1,2 часа прошла 7,8 км. Какой путь пройдет эта лодка за 6 часов по течению реки, если скорость течения равна 1,7 км/ч?

Answer 1

1)7,8/1,2=6,5(км/ч)скорость против течения
2)6,5+3,4=9,9(км/ч)скорость за течением
3)6*9,9=59,4(км)

Answer 2

Problem Analysis

We are given that a motorboat, while moving against the current of a river, traveled a distance of 7.8 km in 1.2 hours. We need to find the distance the boat will travel in 6 hours with the current of the river flowing at a speed of 1.7 km/h.

Solution

To solve this problem, we can use the formula:

Distance = Speed × Time

Let's calculate the speed of the boat while moving against the current and with the current.

1. Speed of the boat against the current: - Distance = 7.8 km - Time = 1.2 hours - Speed = Distance / Time

2. Speed of the current: - Speed = 1.7 km/h

3. Speed of the boat with the current: - Speed = Speed of the boat against the current + Speed of the current

4. Distance traveled by the boat with the current: - Time = 6 hours - Distance = Speed of the boat with the current × Time

Let's calculate the values step by step.

Calculation

1. Speed of the boat against the current: - Distance = 7.8 km - Time = 1.2 hours - Speed = 7.8 km / 1.2 hours = 6.5 km/h 2. Speed of the current: - Speed = 1.7 km/h 3. Speed of the boat with the current: - Speed = Speed of the boat against the current + Speed of the current - Speed = 6.5 km/h + 1.7 km/h = 8.2 km/h

4. Distance traveled by the boat with the current: - Time = 6 hours - Distance = Speed of the boat with the current × Time - Distance = 8.2 km/h × 6 hours = 49.2 km

Answer

The motorboat, while moving with the current of the river flowing at a speed of 1.7 km/h, will travel a distance of 49.2 km in 6 hours.