Question

В полдень от пристани отошел теплоход со скоростью 16км\ч. Через 3 часа вслед ему отошел второй теплоход и через 12 часов догнал первый. Найди скорость второго теплохода. Выполни схему к задаче.

Answer 1

12+3=15 ч был в пути 1 теплоход
16*15=240 км прошёл 1 теплоход
240 :12 = 20км/ч скорость 2 теплохода

Answer 2

Problem Analysis

We are given that a boat departs from a pier at noon with a speed of 16 km/h. After 3 hours, another boat departs from the same pier and catches up to the first boat after 12 hours. We need to find the speed of the second boat.

Solution

Let's assume the speed of the second boat is x km/h.

The first boat travels for 3 hours at a speed of 16 km/h, so it covers a distance of 3 * 16 = 48 km.

The second boat catches up to the first boat after 12 hours. During this time, the first boat has traveled for a total of 3 + 12 = 15 hours. The second boat has traveled for 12 hours.

Since both boats have traveled the same distance when the second boat catches up, we can set up the following equation:

48 + 16 * 15 = x * 12

Simplifying the equation:

48 + 240 = 12x

288 = 12x

x = 288 / 12 = 24

Therefore, the speed of the second boat is 24 km/h.

Diagram

Here is a diagram representing the situation:

First boat: 16 km/h
Second boat: x km/h

After 3 hours:
First boat: 48 km

After 12 hours:
First boat: 48 + 16 * 12 = 240 km
Second boat: x * 12 km

Both boats have traveled the same distance:
48 + 16 * 15 = x * 12

I hope this helps! Let me know if you have any further questions.