Question

Катер отошёл от пристани и двинулся по течению реки. Через 1,5ч он павернул обратно и двигался против течения такое же время. На каком расстоянии от пристани он оказался , если скорость катера в стоячей воде 21,6 км/ч , а скорость течения реки 1,9 км/ч

Answer 1

1. Складываем скорость реки и скорость катера и умножаем на 1,5. Считаем, сколько катер прошел.
2. Вычитаем скорость реки из скорости катера. Умножаем на 1,5.
3. Считаем разницу.

Answer 2

Problem Analysis

We are given the following information: - A boat departs from a dock and moves downstream for 1.5 hours. - The boat then turns back and moves upstream for the same amount of time. - The speed of the boat in still water is 21.6 km/h. - The speed of the river's current is 1.9 km/h.

We need to determine the distance from the dock where the boat ended up.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's break down the problem into two parts: the downstream journey and the upstream journey.

1. Downstream Journey: - The boat is moving with the current, so its effective speed is the sum of the boat's speed in still water and the speed of the current: 21.6 km/h + 1.9 km/h = 23.5 km/h. - The time for the downstream journey is given as 1.5 hours. - Using the formula, the distance covered during the downstream journey is: 23.5 km/h × 1.5 hours = 35.25 km.

2. Upstream Journey: - The boat is moving against the current, so its effective speed is the difference between the boat's speed in still water and the speed of the current: 21.6 km/h - 1.9 km/h = 19.7 km/h. - The time for the upstream journey is also given as 1.5 hours. - Using the formula, the distance covered during the upstream journey is: 19.7 km/h × 1.5 hours = 29.55 km.

To find the total distance from the dock, we need to subtract the distance covered during the upstream journey from the distance