Question

ХЕЛП! Лодка проплывает против 1.4 за 12 мин. Найдите скорость течения и скорость лодки по течению, если скорость лодки по течению превосходит в 1.3 раза скорость лодки против течения

Answer 1

12 мин = 1/5 часа;
скорость против течения=1,4/0,2=7 км/ч;
скорость по течению в 1,3 раза больше, следовательно: 7*1,3=9,1 км/ч
скорость течения: (9,1-7)/2= 1,05 км/ч

Answer 2

2 мин = 1/5 часа;
1,4/0,2=7 (км/ч) - скорость против течения
скорость по течению в 1,3 раза больше, следовательно: 7*1,3=9,1 (км/ч)
(9,1-7)/2= 1,05 (км/ч) - скорость течения: 

Answer 3

Problem Analysis

To find the speed of the current and the speed of the boat in still water, we can use the following information: - The boat travels against the current at a speed of 1.4 units in 12 minutes. - The speed of the boat in still water is 1.3 times the speed of the boat against the current.

Let's denote the speed of the current as c and the speed of the boat in still water as b.

Solution

To find the speed of the current and the speed of the boat in still water, we can set up the following equations:

1. When the boat is traveling against the current: - Speed of the boat = Speed of the current + Speed of the boat in still water - 1.4 = c + b 2. When the boat is traveling with the current: - Speed of the boat = Speed of the boat in still water - Speed of the current - Speed of the boat = 1.3 * (Speed of the boat against the current) - b = 1.3 * (1.4 - c) - b = 1.82 - 1.3c We now have a system of two equations with two unknowns (b and c). We can solve this system of equations to find the values of b and c.

To solve the system of equations, we can substitute the value of b from equation 2 into equation 1:

1.4 = c + (1.82 - 1.3c) 1.4 = 1.82 - 0.3c 0.3c = 1.82 - 1.4 0.3c = 0.42 c = 0.42 / 0.3 c = 1.4

Substituting the value of c back into equation 1, we can find the value of b:

1.4 = 1.4 + b b = 1.4 - 1.4 b = 0

Answer

The speed of the current is 1.4 units and the speed of the boat in still water is 0 units.