The athlete rode 1/3 of the road on a bicycle at a speed of 15 km / h, the rest of the road ran at a speed

The athlete rode 1/3 of the road on a bicycle at a speed of 15 km / h, the rest of the road ran at a speed of 5 km / h. Calculate the average speed along the way.

To find the desired average speed of an athlete along the entire path, we will use the formula: Vav = S / t = S / (t1 + t2) = S / (S1 / V1 + (S – S1) / V2) = S / (S / 3V1 + 2S / 3V2) = 1 / (1 / 3V1 + 2 / 3V2).

Variables: V1 – cycling speed (V1 = 15 km / h); V2 is the athlete’s running speed (V2 = 5 km / h).

Let’s calculate: Vav = 1 / (1 / 3V1 + 2 / 3V2) = 1 / (1 / (3 * 15) + 2 / (3 * 5)) = 6.43 km / h.

Answer: All the way, the athlete moved at an average speed of 6.43 km / h.