Answer:
The average speed of the athlete for the entire competition is approximately 21.23 km/hr
Explanation:
The given parameters of the athlete performance in the triathlon are;
The length the athlete swims = 750 m = 0.75 km
The time the athletes spends swimming = 15 minutes = 0.25 hours
The speed with which the athlete cycles = 40 km/hr.
The time the athletes spends while cycling = 30 minutes = 0.5 hours
The distance the athlete ran = 5 km
The average speed with which the athlete ran = 3 m/s = 10.8 km/hr.
The formula for average speed, s is Average speed = Total distance/(Total time)
The distance, ∑d, the athlete covered in the entire competition is given as follows;
∑d = 0.75 km + 0.5 hr. × 40 km/hr. + 5 km = 0.75 km + 20 km + 5 km = 25.75 km
The distance, ∑t, the athlete spends in the entire competition is given as follows;
∑t = 0.25 hr. + 0.5 hr. + 5 km/(10.8 km/hr.) = 0.25 hr. + 0.5 hr. + 0.463 hr. ≈ 1.213 hr.;
Therefore;
The average speed of the athlete for the entire competition, s = ∑d/∑t = 25.75 km/(1.213 hr.) ≈ 21.23 km/hr.