SECTION 2.7 Further Applications of Linear Equations^149
In Exercises 39 – 42, find the rate on the basis of the information provided. Use a calculator
and round your answers to the nearest hundredth. All events were at the 2008 Olympics.
(Source: World Almanac and Book of Facts.)37.The winner of the 2008 Indianapolis 500
(mile) race was Scott Dixon, who drove
his Dellara-Honda to victory at a rate of
143.567 mph. What was his time (to the
nearest thousandth of an hour)? (Source:
World Almanac and Book of Facts.)38.In 2008, Jimmie Johnson drove his
Chevrolet to victory in the Brickyard
400 (mile) race at a rate of 115.117 mph.
What was his time (to the nearest thou-
sandth of an hour)? (Source: World Al-
manac and Book of Facts.)Event Participant Distance Time
100-m hurdles, women Dawn Harper, USA 100 m 12.54 sec
400-m hurdles, women Melanie Walker, Jamaica 400 m 52.64 sec
400-m hurdles, men Angelo Taylor, USA 400 m 47.25 sec
400-m run, men LaShawn Merritt, USA 400 m 43.75 secSolve each motion problem. See Examples 6 and 7.
43.Atlanta and Cincinnati are 440 mi apart. John leaves Cincinnati, driving toward Atlanta at
an average rate of 60 mph. Pat leaves Atlanta at the same time, driving toward Cincinnati in
her antique auto, averaging 28 mph. How long will it take them to meet?
JohnPtPatPtPatPatPatPatPatPatPatPPatPatPatPatPaPaPPtCincinnati440 mi AtlantaPortland St. Louis2060 mirt d
John 60 t 60 t
Pat 28 t 28 trtd
Plane Leaving 90 t 90 t
Portland
Plane Leaving 116 t 116 t
St. Louis44.St. Louis and Portland are 2060 mi apart. A small plane leaves Portland, traveling toward
St. Louis at an average rate of 90 mph. Another plane leaves St. Louis at the same time,
traveling toward Portland and averaging 116 mph. How long will it take them to meet?