During the first half of the driving time, the car’s speed was 45 km / h, the rest of the time the car moved at a speed of 60 km / h

During the first half of the driving time, the car’s speed was 45 km / h, the rest of the time the car moved at a speed of 60 km / h. What is the average speed of the vehicle along the way?

Average vehicle speed:
Vav. = S / t, where S is the common path (S = S1 + S2, where S1 = 1/2 S, S2 = 1/2 S), t is the total travel time (t = t1 + t2).
S1 = V1 * t1, S2 = V2 * t2, where V1 = 45 km / h, V2 = 60 km / h.
Vehicle movement time:
t1 = S1 / V1 = (1 / 2S) / 45; t2 = S2 / V2 = (1 / 2S) / 60.
Let’s calculate the average speed:
Vav. = S / t = S / ((1 / 2S) / 45 + (1 / 2S) / 60) = S / (0.0111S + 0.0083S) = 1 / 0.0194 = 51.55 km / h.
Answer: The average speed is 51.55 km / h.