Question

Между двумя городами 100 км. Автомобиль с начала проезжает 50 км со скоростью 10км/ч а затем еще 50 км со скоростью 90км/ч. найдите среднею скорость автомобиля

Answer 1

Время в пути t=50/10+50/90=50/9 ч, Vср=100/(50/9/=18 км/час

Answer 2

Calculation of Average Speed

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

Average Speed = Total Distance / Total Time

In this case, the car travels a total distance of 100 km, with the first 50 km covered at a speed of 10 km/h and the remaining 50 km covered at a speed of 90 km/h.

Let's calculate the total time taken for the journey:

Time taken for the first 50 km = Distance / Speed = 50 km / 10 km/h = 5 hours

Time taken for the remaining 50 km = Distance / Speed = 50 km / 90 km/h = 0.5556 hours (rounded to 4 decimal places)

Total Time = Time taken for the first 50 km + Time taken for the remaining 50 km = 5 hours + 0.5556 hours = 5.5556 hours (rounded to 4 decimal places)

Now, let's calculate the average speed:

Average Speed = Total Distance / Total Time = 100 km / 5.5556 hours = 18 km/h (rounded to the nearest whole number)

Therefore, the average speed of the car for the entire journey is 18 km/h.