Answer:
In triathlon an athlete swims 750meter in 15minutes cycles at an average speed of 40km/h for 30minutes and runs 5km at an average speed of 3meter/second find his average speed for the entire competition giving your answer in km/h
The average speed for the entire triathlon = 21.229 km/hr
Explanation:
Calculate the distance covered and time taken in the first part of the Triathlon in Kilometers and hours respectively - Swimming
Distance 750 meters ⇒ 750/100= 0.75Km
Time = 15 minutes ⇒ 15/60 = 0.25 hours
Calculate the distance and time in Km and hours in the second phase:
Time is 30 minutes = 30/60 = 0.5 hours
Speed = 40km/hr
Distance = speed × time = 40km/hr × 0.5 = 20km
Calculate the distance covered and time taken in the last phase of the triathlon: Running
Runs 5 Km - this is the distance
5km = 5000m
Speed = 3 meters/sec
Time = Distance / speed
= 5000 m / 3m/s
= 1666.66666667 s
Convert to hours
1666.66666667 /3600 = 0.46 hours
Final step is to calculate the average speed:
Average speed = total distance travelled / total time taken
Total distance in Km = 0.75 km + 20 km + 5 km = 25.75 km
Total time taken = 0.25 hours + 0.5 hours + 0.46 hours = 1.21296296296 hours
Average speed of the athlete = 25.75 km / 1.21296296296 hours
= 21.229 Km/hr
The average speed for the entire triathlon = 21.229 km/hr