+0  
 
0
288
2
avatar

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. Please help finish

Guest May 6, 2017
 #1
avatar+90141 
+1

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. Please 

 

Let's first find out how many minutes it took him to run the first 2 K....

 

Since   Distance / Rate  = Time....we have

 

2K / ( 12 k/hr )   =   1/6 hr

 

 

So....this means that he must run the last 8K in 5/6 hr....so we have

 

Distance /Time   = Rate

 

8k / (5/6) hr  =    

 

8 / (5/6)  =

 

8 * (6/5)  =

 

48/5  =  

 

9.6  k / hr

 

 

cool cool cool

CPhill  May 6, 2017
 #2
avatar
+1

Thanks

Guest May 6, 2017

41 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.