Question

Водитель автомобиля ехал из пункта А в пункт Б. Первые два часа он ехал со скоростью 90 км/ч , потом он один час отдыхал, а затем, следуя со скоростью 60 км/ч , через три часа прибыл в пункт Б. Расстояние между пунктами А и Б 240 км по прямой. Какова средняя путевая скорость и средняя скорость автомобиля.

Answer 1

$V_{1} = 90 V_{2} = 60 t _{1} = 2 t_{2} = 3$
V средняя путевая - ?
V средняя автомобиля - ?   
V средняя - S1+ S2/t1+t2.
V средняя путевая = 180(90 * 2) + 180(60*30) / 5(2+3) = 72 км\час = 20 м\с
V средняя автомобиля = 180 +180\ (1+2+3 так как он час ещё отдыхал) = 360\6 = 60 км\час.

Answer 2

Calculation of Average Speed

To calculate the average speed of the driver, we need to determine the total time taken and the total distance traveled.

Given information: - The driver traveled from point A to point B, a distance of 240 km. - The driver initially traveled at a speed of 90 km/h for 2 hours. - The driver then rested for 1 hour. - Finally, the driver traveled at a speed of 60 km/h for 3 hours.

To calculate the average speed, we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the total time taken and the average speed.

1. The driver traveled at a speed of 90 km/h for 2 hours, covering a distance of 90 km/h * 2 hours = 180 km. 2. The driver rested for 1 hour. 3. The driver then traveled at a speed of 60 km/h for 3 hours, covering a distance of 60 km/h * 3 hours = 180 km.

The total distance traveled is 180 km + 180 km = 360 km.

The total time taken is 2 hours + 1 hour + 3 hours = 6 hours.

Using the formula, we can calculate the average speed:

Average Speed = Total Distance / Total Time = 360 km / 6 hours = 60 km/h.

Therefore, the average speed of the car is 60 km/h.

Please note that the average speed is calculated by dividing the total distance by the total time, regardless of the variations in speed during the journey.