Converting Miles/Hour to Feet

Date: 08/14/97 at 19:19:52
From: augie
Subject: Travel, mph to feet

If my father is traveling in his car at 45 mph, how long will it take 
him to travel 100 feet?

I know that there are 5280 feet in one mile and that at 60 mph you can 
go a mile in one minute, but I'm not sure what to do next.

Can you help?

Augie

Date: 08/15/97 at 15:41:17
From: Doctor Beth
Subject: Re: Travel, mph to feet

Thanks for the question!  

To figure this out, let's first figure out how many feet your father 
travels in a second. Since he's going 45 miles per hour, and there are 
5280 feet in a mile, he's actually going 45*5280 feet per hour, which 
is 237,600 feet per hour. (I used a calculator to multiply it, but you 
could do it by hand.)  

But there are 3600 seconds in an hour, since there are 60 minutes in 
an hour and 60 seconds in a minute. So to find out how many feet he 
travels in a second, we'll divide 237600 by 3600 and get 66. 

So now we know that your father is traveling 66 feet per second.  To 
travel 100 feet, it takes him 100 divided by 66 seconds, or about 
1.515151... seconds.  

I hope this helps!

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