Question

Пешеход прошел половину пути между пунктами А и Б со скоростью V1, а вторую половину пути - со скоростью V2 Выведите формулу средней скорости пешехода на всем пути

Answer 1

Vср=S/tобщ    tобщ=t1+t2    t1=s/2v1   t2=s/2v2
Vср=2s/s(1/v1+1/v2)=2v1*v2/(v1+v2)

Answer 2

Calculation of Average Speed

To calculate the average speed of a pedestrian who walks half the distance between points A and B at speed V1, and the other half at speed V2, we can use the formula:

Average Speed = Total Distance / Total Time

The total distance is the sum of the distances covered at each speed, and the total time is the sum of the times taken at each speed.

Let's denote the total distance as D and the total time as T.

The distance covered at speed V1 is half the total distance, which is D/2. The time taken to cover this distance is D/2V1.

Similarly, the distance covered at speed V2 is also half the total distance, which is D/2. The time taken to cover this distance is D/2V2.

Therefore, the total distance is D = D/2 + D/2 = D, and the total time is T = D/2V1 + D/2V2.

Substituting these values into the formula for average speed, we get:

Average Speed = D / T = D / (D/2V1 + D/2V2)

Simplifying the equation further, we can factor out D/2 from the denominator:

Average Speed = D / T = 2D / (D(V1 + V2))

Finally, we can simplify the equation to:

Average Speed = (V1 + V2) / 2

Therefore, the formula for the average speed of the pedestrian on the entire journey is (V1 + V2) / 2.