Question

Помогите срочно!! Корабль прошел по течению реки 507 км и против течения реки 108 км. за 19 ч. За это время он мог пройти 234 км по течению и 234 км против течения. Найдите скорость корабля против течения реки.

Answer 1

Ответ:

18

Объяснение:

x - скорость корабля по течению реки, км/ч.

y - скорость корабля против течения реки, км/ч.

Система уравнений:

507/x +108/y=19

234/x +234/y=19

507/x +108/y=234/x +234/y

273/x=126/y                     |21

x=13/6 ·y

234/(13/6 ·y) +234/y=19

234 +234·13/6=19·13/6 ·y                 |13

18+39=19/6 ·y

y=57·6/19=3·6=18 км/ч

Answer 2

Problem Analysis

We are given that a ship traveled 507 km downstream and 108 km upstream in a total of 19 hours. Additionally, we are told that in this time, the ship could have traveled 234 km downstream and 234 km upstream. We need to find the speed of the ship against the current of the river.

Solution

Let's assume the speed of the ship in still water is x km/h, and the speed of the current is y km/h.

When the ship is traveling downstream, its effective speed is the sum of its speed in still water and the speed of the current. Therefore, the effective speed downstream is (x + y) km/h.

When the ship is traveling upstream, its effective speed is the difference between its speed in still water and the speed of the current. Therefore, the effective speed upstream is (x - y) km/h.

We can use the formula distance = speed × time to calculate the time taken for each leg of the journey