Antti entered a 10-kilometer race. His goal is to finish in one hour. He starts off sprinting and completes the first 2 kilometers of the race at an average speed of 12 kilometers per hour. To achieve his goal of a one-hour finish time, what average speed must Antti maintain for the last 8 kilometers of the race? Enter your answer as a number in decimal form, without units.
+37084 There is still 8 km to go
2 km / 12 km/hr = 1/6 hr = 10 minutes
50 Minutes (5/6 hr) to finish 8 km 8 km/ 5/6 hr = 48/5 km/ hr = 9.6 km/hr
+14985 Hello guest!
Antti entered a 10-kilometer race. His goal is to finish in one hour. He starts off sprinting and completes the first 2 kilometers of the race at an average speed of 12 kilometers per hour. To achieve his goal of a one-hour finish time, what average speed must Antti maintain for the last 8 kilometers of the race? Enter your answer as a number in decimal form, without units.
t2 = s2/ v2 = 2km / (12km/h) = 1/6 h
t8 = s8 / v8
v8 = s8 / t8 = 8km / (5/6 h) = 9.6 km/h
Antti have to walk 8 km with 9.6 km/h average speed.
Greeting asinus :- )
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