The first half of the time the car was moving at an average speed of v1 = 40 km / h, the second – at an average speed of v2 = 60 km / h

The first half of the time the car was moving at an average speed of v1 = 40 km / h, the second – at an average speed of v2 = 60 km / h. Determine the average speed (v) of the car along the way.

A car travels different distances at regular intervals.
S1 = v1 * t / 2
S2 = v2 * t / 2

Let’s substitute the average speed in the formula:
v0 = (S1 + S2) / 2
v0 = [v1 * t / 2 + v2 * t / 2] / 2
v0 = v1 + v2 / 2

The average speed for this case turned out to be equal to the arithmetic mean of the speeds.
Let’s substitute the values of the velocities and carry out the calculations:
v0 = 40 + 60/2 = 50 km / h