Question

Из точки А выплыла лодка по реке.Течение реки 5 км/ч. Скорость 1 лодки 10 км/ч Из пункта В вышла 2 лодка.Скорость 2 лодки 20 км/ч против течения.Найдите через сколько они встретились

Answer 1

Через 5 часов встретятся они
10+5=15
20-5=15
15+15=30
150\30=5

Answer 2

Problem Analysis

We have two boats, Boat 1 and Boat 2, starting from points A and B respectively. Boat 1 is moving downstream with a speed of 10 km/h, while Boat 2 is moving upstream against the current with a speed of 20 km/h. We need to find out how long it will take for the two boats to meet.

Solution

To solve this problem, we can use the concept of relative velocity. The relative velocity of Boat 2 with respect to Boat 1 is the sum of their individual velocities. Since Boat 2 is moving against the current, we need to subtract the speed of the current from its velocity.

Let's calculate the relative velocity:

Relative velocity = (Velocity of Boat 1) + (Velocity of Boat 2) - (Speed of the current)

Given: - Velocity of Boat 1 = 10 km/h - Velocity of Boat 2 = 20 km/h - Speed of the current = 5 km/h

Substituting the values into the formula:

Relative velocity = 10 km/h + 20 km/h - 5 km/h = 25 km/h

Now, we can calculate the time it will take for the two boats to meet by dividing the distance between the two points by the relative velocity.

Since we don't have the distance between points A and B, we cannot provide an exact answer. However, we can provide the formula to calculate the time:

Time = Distance / Relative velocity

Please provide the distance between points A and B, and we can calculate the time it will take for the two boats to meet.