Question

Мальчик съехал на санках с горы длинной 40 и за 10 с,а затем проехал по горизонтальному участку ещё 20 м .Найти среднюю скорость на всём пути

Answer 1

T2=2L2/V1=L1*t1/V1
t2=10*20/40=5 (м/с)
Vср=L1+L2/t+t2
Vср=40+20/10+5=4 (м/с)

Answer 2

Calculation of Average Speed

To find the average speed of the boy on his sled, we need to calculate the total distance traveled and the total time taken.

The boy first traveled down a hill for a distance of 40 meters in 10 seconds. Then, he traveled on a horizontal section for an additional 20 meters.

To calculate the total distance traveled, we add the distance on the hill (40 meters) to the distance on the horizontal section (20 meters):

Total distance = 40 meters + 20 meters = 60 meters

To calculate the total time taken, we add the time taken on the hill (10 seconds) to the time taken on the horizontal section (0 seconds, as the boy is not moving horizontally):

Total time = 10 seconds + 0 seconds = 10 seconds

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

Average speed = Total distance / Total time

Substituting the values we calculated:

Average speed = 60 meters / 10 seconds = 6 meters per second

Therefore, the average speed of the boy on his sled for the entire journey is 6 meters per second.

Please note that the sources provided did not contain specific information related to this calculation.