Question

Быструю реку можно переплыть от берега до берега за 4 минуты, если плыть со скоростью 90 метров в минуту. Сколько времени потребуется для этого Оле, если она будет плыть со скоростью 60 метров в минуту? Срешением пожалуйста

Answer 1

Первое действие это 4*90=360(м)
Второе действие это 360/60=6(мин.)
Ответ:6минут потребуется Оле,что-бы переплыть реку.

Answer 2

Problem Analysis

We are given that a fast river can be crossed from one bank to the other in 4 minutes at a speed of 90 meters per minute. We need to find out how long it will take for Ole to cross the river at a speed of 60 meters per minute.

Solution

To solve this problem, we can use the concept of relative velocity.

When crossing a river, the swimmer needs to account for the speed of the river current in addition to their own swimming speed. The resultant velocity is the vector sum of the swimmer's velocity and the river current velocity.

Let's assume the width of the river is 'd' meters.

At a speed of 90 meters per minute, the swimmer crosses the river in 4 minutes. Therefore, the total distance covered by the swimmer is 90 * 4 = 360 meters.

Using the formula: distance = speed * time, we can find the time taken by Ole to cross the river at a speed of 60 meters per minute.

Let's calculate the time taken by Ole to cross the river:

Time taken by Ole = Total distance / Ole's speed

Time taken by Ole = 360 meters / 60 meters per minute

Time taken by Ole = 6 minutes

Therefore, it will take Ole 6 minutes to cross the river at a speed of 60 meters per minute.

Answer

Ole will take 6 minutes to cross the river at a speed of 60 meters per minute.