Question

Расстояние между двумя пристанями 36 км,катер прошел это расстояние по течению реки за 2 ч,а против течения за 3 ч. Какова скорость течения реки? Ответ_________км/ч

Answer 1

1) 18 КМ.ЧАС СКОРОСТЬ КАТЕРА ПО ТЕЧЕНИЮ
2) 12 КМ. ЧАС ПРОТИВ ТЕЧЕНИЯ
3) 18 - 12    6 КМ ЧАС СКОРОСТЬ ТЕЧЕНИЯ РЕКИ

Answer 2

Problem Analysis

We are given the following information: - The distance between two ports is 36 km. - The boat traveled this distance downstream in 2 hours. - The boat traveled this distance upstream in 3 hours.

We need to find the speed of the river's current.

Solution

Let's assume the speed of the boat in still water is B km/h, and the speed of the river's current is C km/h.

When the boat is traveling downstream (with the current), its effective speed is the sum of the boat's speed and the current's speed: (B + C) km/h.

When the boat is traveling upstream (against the current), its effective speed is the difference between the boat's speed and the current's speed: (B - C) km/h.

We can use the formula distance = speed × time to create two equations based on the given information:

1. When the boat is traveling downstream: - Distance = 36 km - Speed = (B + C) km/h - Time = 2 hours - Therefore, the equation is: 36 = (B + C) × 2.

2. When the boat is traveling upstream: - Distance = 36 km - Speed = (B - C) km/h - Time = 3 hours - Therefore, the equation is: 36 = (B - C) × 3.

We can solve these two equations to find the values of B and C.

Let's solve the equations step by step:

1. From the first equation, we have: 36 = (B + C) × 2. - Simplifying, we get: 18 = B + C.

2. From the second equation, we have: 36 = (B - C) × 3. - Simplifying, we get: 12 = B - C.