Question

Расстояние между пристанями А и В равно 76 км Из пристани А вниз по течению отправили плот. Из пристани В, навстречу с плотом, отплыла моторная лодка. Моторная лодка и плот встретилисть через 4 часов. Какова собственная скорость лодки (в км/ч), если скорость течения реки равна 2 км/ч?

Answer 1

Ответ:

19

Объяснение:

x - скорость лодки, км/ч.

4·2+4(x-2)=76 |4

2+x-2=19

x=19 км/ч

Answer 2

Problem Analysis

We are given the following information: - The distance between two ports, A and B, is 76 km. - A raft is sent downstream from port A. - A motorboat departs from port B towards the raft. - The raft and motorboat meet after 4 hours. - The speed of the river current is 2 km/h.

We need to find the speed of the motorboat.

Solution

Let's assume the speed of the motorboat is x km/h.

Since the raft is moving downstream, its speed relative to the river current will be the sum of the speed of the river current and the speed of the motorboat. Therefore, the speed of the raft is x + 2 km/h.

We know that the distance between the ports is 76 km and the time it takes for the raft and motorboat to meet is 4 hours. We can use the formula distance = speed × time to create an equation:

76 = (x + 2) × 4

Now, let's solve this equation to find the value of x.

76 = 4(x + 2) 76 = 4x + 8 4x = 76 - 8 4x = 68 x = 68/4 x = 17

Therefore, the speed of the motorboat is 17 km/h.

Answer

The speed of the motorboat is 17 km/h.