Question

Из города а в город б расстояние между которыми 300 км выехал автомобиль первую половину пути он ехал со скоростью 50 кмч а вторую со скоростью 30 кмч найдите среднюю скорость автомобиля

Answer 1

Первая половина пути:
150:50=3 часа

вторая половина пути:
150:30=5 часов

средняя скорость - это все расстояние, деленное на все время:

300:8=37.5км/ч

Ответ: 37.5 км/ч

Answer 2

Problem Analysis

We are given that a car travels a distance of 300 km from city A to city B. The car travels the first half of the distance at a speed of 50 km/h and the second half at a speed of 30 km/h. We need to find the average speed of the car.

Solution

To find the average speed of the car, we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the total distance and total time.

The total distance is given as 300 km.

To find the total time, we need to calculate the time taken for each half of the distance and then add them together.

The time taken for the first half of the distance can be calculated using the formula:

Time = Distance / Speed

For the first half of the distance, the speed is 50 km/h. Therefore, the time taken for the first half is:

Time for first half = (300 km / 2) / 50 km/h = 3 hours

Similarly, the time taken for the second half of the distance can be calculated using the formula:

Time for second half = (300 km / 2) / 30 km/h = 5 hours

Now, we can calculate the total time:

Total Time = Time for first half + Time for second half = 3 hours + 5 hours = 8 hours

Finally, we can calculate the average speed using the formula:

Average Speed = Total Distance / Total Time = 300 km / 8 hours = 37.5 km/h

Therefore, the average speed of the car is 37.5 km/h.

Answer

The average speed of the car is 37.5 km/h.