Question

Две моторные лодки в 14:00 отошли от причала на озере в противоположных направлениях скорость первой лодки 28 километров час через 30 минут расстояние между ними было 26 километров 500 метров Найдите скорость второй лодки

Answer 1

V1 (cкорость первой лодки) = 28км\ч
V2 (скорость второй лодки) = ?
t1=t2=0.5ч (30 мин = 0,5 часов)
S(расстояние, на которое разошлись лодки) = 26,5 км
Найдем расстояние, на которое ушла первая лодка от точки отправления:
V1*t1=S1 
28*0,5= 14 км
Вычтем расстояние S1 из общего расстояния S:
S - S1 = S2 
25,5 - 14 = 12,5 км (прошла вторая лодка)
Найдем скорость второй лодки:
S2/t2=V2 
12,5/0,5=25 км\ч

Ответ: Скорость второй лодки 25 км/час

Answer 2

Problem Analysis

We are given that two motorboats departed from a pier on a lake at 14:00 in opposite directions. The speed of the first boat is 28 kilometers per hour, and after 30 minutes, the distance between the two boats was 26 kilometers and 500 meters. We need to find the speed of the second boat.

Solution

Let's break down the problem and solve it step by step.

1. Convert the distance between the two boats from kilometers and meters to just meters for consistency. We have 26 kilometers and 500 meters, which is equal to 26,500 meters.

2. Convert the time of 30 minutes to hours. Since there are 60 minutes in an hour, 30 minutes is equal to 0.5 hours.

3. Use the formula: speed = distance / time to find the speed of the first boat. The distance is 26,500 meters, and the time is 0.5 hours.

4. Now, we know the speed of the first boat, which is 28 kilometers per hour. Let's denote the speed of the second boat as x (in kilometers per hour).

5. Since the boats are moving in opposite directions, the relative speed between them is the sum of their individual speeds. So, the relative speed is 28 + x kilometers per hour.

6. We can use the formula: speed = distance / time again to find the time it takes for the boats to be 26,500 meters apart. The distance is 26,500 meters, and the speed is the relative speed of 28 + x kilometers per hour.

7. Solve the equation for time to find the time it takes for the boats to be 26,500 meters apart.

8. Now, we have the time it takes for the boats to be 26,500 meters apart, and we know that the first boat traveled for 0.5 hours. Subtracting the time traveled by the first boat from the total time will give us the time traveled by the second boat.

9. Finally, we can use the formula: speed = distance / time to find the speed of the second boat. The distance is 26,500 meters, and the time is the time traveled by the second boat.

Let's calculate the speed of the second boat using the steps outlined above.

Calculation

1. Distance between the two boats: 26,500 meters. 2. Time: 0.5 hours. 3. Speed of the first boat: 28 kilometers per hour. 4. Relative speed of the two boats: 28 + x kilometers per hour. 5. Time for the boats to be 26,500 meters apart: t hours. 6. Time traveled by the second boat: t - 0.5 hours. 7. Speed of the second boat: distance / time = 26,500 meters / (t - 0.5) hours.

Let's solve for the speed of the second boat.

Solution

The speed of the second boat is 26,500 / (t - 0.5) kilometers per hour.

Please note that we need the value of t to calculate the speed of the second boat. The value of t can be obtained by solving the equation for time in step 7.

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