Question

2) A bike racer completed a 20.0 kilometer race. She pedaled the first 5.0 kilometers with an average speed of 20.0 km/hr. She pedaled the next 5.0 kilometers (which were uphill) at an average speed of 10.0 km/hr. She completed the next 5.0 kilometers (which were downhill) at an average speed of 25.0 km/hr and the final 5.0 kilometers she covered at an average speed of 20.0 km/houra) (2point) How long did it take the biker to complete the race

Answer 1

Explanation:

Time = distance/speed

Considering the first stage,

Speed = 20km/hr

Distance = 5km

Time = 5/20 = 0.25 hour

Considering the second stage,

Speed = 10km/hr

Distance = 5km

Time = 5/10 = 0.5 hour

Considering the third stage,

Speed = 25km/hr

Distance = 5km

Time = 5/25 = 0.2 hour

Considering the third stage,

Speed = 20km/hr

Distance = 5km

Time = 5/20 = 0.25 hour

Therefore, the time it took the biker to complete the race is

0.25 + 0.5 + 0.2 + 0.25 = 1.2 hours