Question

ПОМОГИТЕ ПОЖАЛУСТА!Рыболов проплыл на лодке от пристани некоторое расстояние вверх по течению реки, затем бросил якорь, 2 часа ловил рыбу и вернулся обратно через 5 часов от начала путешествия. На какое расстояние от пристани он отплыл, если скорость течения реки равна 4 км/ч, а собственная скорость лодки 6 км/ч?между двумя пристанями по реке равно 24 км. Моторная лодка прошла от одной пристани до другой, сделала стоянку на 1 ч 40 мин и вернулась обратно. Всё путешествие заняло 6целых 2/3 ч. Найдите скорость течения реки, если известно, что скорость моторной лодки в стоячей воде равна 10 км/ч.

Answer 1

Х расстояние
х/2+х/10+2=5
5х+х+20=50
6х=30
х=5 км

х скорость течения
10=х по течению   10-х против течения
24/(10+х)+24/(10-х)+1 2/3=6 2/3
24/(10+х)+24/(10-х)=5
Избавляемся от знаменателя, получаем  500-480=5х²
х²=4
х=2км/час скорость течения

Answer 2

Problem Statement

A fisherman sets out on a boat from a dock and travels a certain distance upstream along a river. He then drops anchor and spends 2 hours fishing before returning back to the dock, which takes him 5 hours from the start of his journey. The distance between the two docks along the river is 24 km. The speed of the river's current is 4 km/h, and the speed of the fisherman's boat is 6 km/h. We need to find out the distance the fisherman traveled from the dock.

Solution

To solve this problem, we can use the concept of relative velocity. Let's break down the problem into two parts: the upstream journey and the downstream journey.

# Upstream Journey

During the upstream journey, the fisherman's boat is moving against the current of the river. The effective speed of the boat is the difference between the speed of the boat and the speed of the current. In this case, the effective speed is 6 km/h - 4 km/h = 2 km/h.

Let's assume the distance traveled by the fisherman upstream is x km. The time taken for the upstream journey can be calculated using the formula:

Time = Distance / Speed

So, the time taken for the upstream journey is x / 2 hours.

# Downstream Journey

During the downstream journey, the fisherman's boat is moving with the current of the river. The effective speed of the boat is the sum of the speed of the boat and the speed of the current. In this case, the effective speed is 6 km/h + 4 km/h = 10 km/h.

The time taken for the downstream journey is given as 5 hours.

# Total Distance Traveled

The total distance traveled by the fisherman is the sum of the distances traveled during the upstream and downstream journeys. So, the total distance is:

Total Distance = Distance Upstream + Distance Downstream

We can calculate the distance upstream using the formula:

Distance Upstream = Speed Upstream * Time Upstream

And the distance downstream using the formula:

Distance Downstream = Speed Downstream * Time Downstream

Substituting the values, we get:

Distance Upstream = 2 * (x / 2) = x km

Distance Downstream = 10 * 5 = 50 km

Therefore, the total distance traveled is:

Total Distance = x + 50 km

Since the total distance traveled is equal to the distance between the two docks (24 km), we can set up the equation:

x + 50 = 24

Solving this equation, we find:

x = 24 - 50 = -26 km

However, a negative distance doesn't make sense in this context. It indicates that the fisherman did not travel upstream at all. This could be due to an error in the problem statement or the assumptions made. Please double-check the problem statement and the given values to ensure their accuracy.

If you have any further questions, please let me know!