Average Speed on a Race Track Circuit

Date: 6/30/96 at 14:8:23
From: vico Minnocci
Subject: Race Track Speed

My Dad and I were trying to figure out how race track organizers 
figure out on average speed on a circuit.  Given the distance (4.260 
km) and time (1.15.989 min/sec) we couldn't use the d/t=average speed 
formula.  The answer we got is not even close to the actual speed that 
the organizers posted... can you please help us?

Thanks 
    Vico

Date: 7/5/96 at 22:25:39
From: Doctor Robert
Subject: Re: Race Track Speed

You should be able to use the d/t formula, but you must be sure to use 
the correct units so that your answer agrees with the organizer's 
calculations. 

To find the average speed from the data given we have 
v = 4.260/(1+15.989/60) which is equal to approx 3.3636 km/min.  
To get km/hr, we multipy this by 60 since there are 60 minutes in an 
hour.  The calculation gives 201.8 km/hr.  This is roughly 126 mi/hr.  
This is an AVERAGE speed.  The race drivers may drive a certain lap 
quite a bit faster or quite a bit slower than the average. 

By the way, 1 minute and 15.989 seconds is 1+15.989/60 minutes. 
I hope that this helps.

-Doctor Robert,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/