Question

Автомобиль первую часть пути(30 км) прошел со средней скоростью 15 м/с. Остальную часть пути(40 км) он прошел за 1 час. С какой средней скоростью двигался автомобиль на всем пути?

Answer 1

Чтобы определить среднюю скорость, нужно весь путь разделить на все время. 
vср=S / t. 
S=S1+S2. 
S=30+40=70км=70000м.. 
Время на 1 участке: 
t1=S1 / v1. 
t1=3000 / 15=2000c.. 
t=t1+t2. 
t=2000+3600=5600c. 
vср=70000 / 5600=12,5м/c. (45км/ч).

Answer 2

30км:15 м/с=30000м:15 м/с=2000с-время затраченное в первой части пути

1 ч=3600с-время затраченное во 2 части части пути

2000с+3600с=5600с-общее время затраченное в пути

30 км+40 км=30000м+40000м=70000м-всего пройдено пути

70000м:5600с=12.5м/с=45км/ч- средняя скорость автомобиля на всем пути.

Answer 3

Problem Analysis

We are given that a car traveled the first part of the journey (30 km) at an average speed of 15 m/s and the remaining part of the journey (40 km) in 1 hour. We need to find the average speed of the car for the entire journey.

Solution

To find the average speed for the entire journey, we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the total distance and total time for the journey.

The total distance is the sum of the distances traveled in the first and second parts of the journey:

Total Distance = Distance Part 1 + Distance Part 2

The distance traveled in the first part of the journey is given as 30 km.

The distance traveled in the second part of the journey is given as 40 km.

Therefore, the total distance is:

Total Distance = 30 km + 40 km

Now, let's calculate the total time for the journey.

The time taken for the first part of the journey can be calculated using the formula:

Time Part 1 = Distance Part 1 / Speed Part 1

The distance traveled in the first part of the journey is 30 km, and the speed is given as 15 m/s. We need to convert the speed to km/h to match the distance unit.

Speed Part 1 = 15 m/s * (3600 s/1 h) * (1 km/1000 m)

Now, we can calculate the time taken for the first part of the journey:

Time Part 1 = 30 km / (15 m/s * (3600 s/1 h) * (1 km/1000 m))

The time taken for the second part of the journey is given as 1 hour.

Therefore, the total time for the journey is:

Total Time = Time Part 1 + Time Part 2

Finally, we can calculate the average speed for the entire journey using the formula:

**Average Speed = Total Distance / Total