Question

От одной пристани одновременно в противоположном направлении отплыли теплоход и катер. через 2ч пути расстояние между ними было 120 км. С какой средней скоростью плыл теплоход,если его скорость была в 2 раза меньше, чем скорость катера

Answer 1

120 км:2 час=60 км/час (скорость удаления друг от друга, или сумма скоростей) (V=S:t)
60 км/час:(2 части+1 часть)=60:3=20 км/час (скорость теплохода)
20 км/час*2=40 км/час (скорость катера)
Ответ: скорость теплохода 20 км/час, скорость катера - 40 км/час

Answer 2

Problem Analysis

We are given that a steamboat and a motorboat depart from the same dock in opposite directions. After 2 hours of travel, the distance between them is 120 km. We need to find the average speed of the steamboat if its speed is half that of the motorboat.

Solution

Let's assume the speed of the motorboat is x km/h. According to the problem, the speed of the steamboat is half that of the motorboat, so the speed of the steamboat is x/2 km/h.

We know that speed is equal to distance divided by time. After 2 hours of travel, the distance between the steamboat and the motorboat is 120 km. Therefore, we can set up the following equation:

2(x/2) + 2x = 120

Simplifying the equation, we get:

x + 2x = 120

3x = 120

x = 40

So, the speed of the motorboat is 40 km/h, and the speed of the steamboat is half that, which is 20 km/h.

Therefore, the steamboat traveled at an average speed of 20 km/h.

Answer

The steamboat traveled at an average speed of 20 km/h.