Cars Leaving at Different Times
Date: 09/28/2003 at 18:39:43 From: Ryan Subject: d=rt Two cars leave a garage traveling in opposite directions. One car leaves at 8 am and averages 60 mph. The other car leaves at 9 am and averages 50 mph. At what time will they be 225 miles apart? I realize that d = rt. I know you have to add thee speeds so that you can divide it against the miles. But all the examples in my book have the cars leaving at the same time, not at different times. I'm not sure how to deal with that.
Date: 09/28/2003 at 20:14:22 From: Doctor Terrel Subject: Re: d=rt Hi Ryan, Yes, I know what you mean. The problem wants you to "think out of the book". Try this. Let t = the time in hours traveled by the 2nd car. Then how long (or how many hours) does the first car travel? When you know that, you can use d = rt. Or try another idea. How far down the road is the first car BEFORE the 2nd car even starts? Is that enough to get started? - Doctor Terrel, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.