Question

Пожалуйста помогите с задачей)Від двох пристаней одночасно назустріч один одному вирушили човен і теплохід. Човен, власна шв.якого 10,8 км/год, рухався за течією річки, а теплохід pid.30,2 км/год, проти течії. Через скільки год вони зустрінуться, якщо відстань між пристанями 205 км. а швидкість течіі 2.4 км/ год

Answer 1

Скорость сближения 10,8+30,2=41 t=205/41=5 ответ они встретятся через 5 часов

Answer 2

Problem Analysis

To solve this problem, we need to find the time it takes for a boat and a steamer to meet when they start from two piers and move towards each other. The boat's speed is 10.8 km/h downstream, the steamer's speed is 30.2 km/h upstream, the distance between the piers is 205 km, and the river's speed is 2.4 km/h.

Solution

Let's denote: - t as the time it takes for the boat and the steamer to meet, - d as the distance traveled by the boat, - r as the river's speed.

The boat's speed relative to the water is 10.8 km/h, and the river's speed is 2.4 km/h downstream. Therefore, the boat's speed relative to the ground is 10.8 - 2.4 = 8.4 km/h.

The steamer's speed relative to the water is 30.2 km/h, and the river's speed is 2.4 km/h upstream. Therefore, the steamer's speed relative to the ground is 30.2 + 2.4 = 32.6 km/h.

The boat and the steamer are moving towards each other, so their speeds are additive. The total speed at which they are approaching each other is 8.4 km/h + 32.6 km/h = 41 km/h.

We can use the formula: distance = speed × time to find the time it takes for them to meet.

Calculation

The time it takes for the boat and the steamer to meet is: t = distance / total speed t = 205 km / 41 km/h t = 5 hours

Therefore, they will meet in 5 hours.

I hope this helps! If you have further questions, feel free to ask.