Intermediate Algebra (6th Edition)

Published by Pearson
ISBN 10: 0321785045
ISBN 13: 978-0-32178-504-6

Chapter 8 - Section 8.3 - Solving Equations by Using Quadratic Methods - Exercise Set - Page 504: 89b

Answer

11.612 meters/second

Work Step by Step

Voeckler was .0034 m/s faster than Contador Contador took 3 seconds more than Voeckler Voeckler: $119*1000 = (x+.0034)*t$ Contador: $119*1000 = x*(t+3)$ $119000 = xt + .0034t$ $119000 = xt + 3x$ $xt + .0034t = xt +3x$ $.0034t = 3x$ $.0034t/3 = 3x/3$ $.0011333333t = x$ $119000 = (x+.0034)*t$ $119000 = (.0011333333t+.0034)*t$ $119000 = (.0011333333t^2+.0034t)$ $119000-(.0011333333t^2+.0034t)=.0011333333t^2+.0034t-(.0011333333t^2+.0034t)$ $119000-.0011333333t^2+.0034t=0$ $-.0011333333t^2+.0034t+119000=0$ A graphing calculator showed $t= -10245.451$ and $t=10248.451$. However, we ignore the first value of $t$ since we can't have negative time. $t=10248.451$ This is the same as 2.846 hours Voeckler: $119*1000 = (x+.0034)*t$ $119000 = (x+.0034)*10248.451$ $119000/10248.451 = (x+.0034)*10248.451/10248.451$ $11.6115 = x+.0034$ $11.6115 - .0034 = x+.0034-.0034$ $11.6081 = x$ We needed Contador's speed--$11.6115$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.