Question

S1=80км V1=70км/ч S2=70км V2=60км/ч Vсредний-?

Answer 1

Vср = (2*v1*v2)/(v2+v1)
(2*70km/h*60km/h)/(60km/h+70km/h)
(2*4200km/h)/(130km/h)
(8400km/h)/(130km/h)
~~64km/h

Я не знаю, работает ли эта формула с разными S

Answer 2

To find the average speed, we need to calculate the total distance traveled and the total time taken. We can do this using the following formula:

average speed = total distance / total time

First, let's calculate the total distance. The total distance is the sum of S1 and S2:

total distance = S1 + S2 total distance = 80 km + 70 km total distance = 150 km

Next, let's calculate the total time taken. We can use the following formula:

total time = time taken for S1 + time taken for S2

We can calculate the time taken for each distance using the formula:

time = distance / speed

For S1:

time taken for S1 = S1 / V1 time taken for S1 = 80 km / 70 km/h time taken for S1 = 1.143 hours

For S2:

time taken for S2 = S2 / V2 time taken for S2 = 70 km / 60 km/h time taken for S2 = 1.167 hours

Now, let's add the two times together to get the total time:

total time = time taken for S1 + time taken for S2 total time = 1.143 hours + 1.167 hours total time = 2.31 hours

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

average speed = total distance / total time average speed = 150 km / 2.31 hours average speed = 64.94 km/h (rounded to two decimal places)

Therefore, the average speed for the entire journey is approximately 64.94 km/h.