SOLUTION: The distance you travel is a function of your average speed and the time you travelled at that speed. Two cars left Sequoia two hours apart. The first car travelled at 30 mph and

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Question 921102: The distance you travel is a function of your average speed and the time you travelled at that speed. Two cars left Sequoia two hours apart. The first car travelled at 30 mph and the second car travelled at 40 mph. How long before both cars travelled the same distance>
Thanks,
buntcake49@sbcglobal.net
Found 2 solutions by josmiceli, stanbon:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The 1st car's head start is:
+d%5B1%5D+=+30%2A2+
+d%5B1%5D+=+60+
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Start a stopwatch when the 2nd car leaves
Let +t+ = the time on the stopwatch
when the cars have traveled the same distance
Let +d+ = the distance the 2nd car travels
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1st car's equation:
(1) +d+-+60+=+30t+
2nd car's equation:
(2) +d+=+40t+
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By substitution:
(1) +40t+-+60+=+30t+
(1) +10t+=+60+
(1) +t+=+6+
In +2+%2B+6+=+8+ hrs after the 1st car leaves
both cars have traveled the same distance
-----------------
check:
(2) +d+=+40%2A6+
(2) +d+=240+ mi
and
(1) +d+-+60+=+30%2A6+
(1) +d+=+180+%2B+60+
(1) +d+=+240+
OK
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Note that the 1st car travels +240+-+60+=+180+ mi
during the time the 2nd car travels +240+ mi,
but the total miles for each car is the same: +240+ mi





Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The distance you travel is a function of your average speed and the time you travelled at that speed. Two cars left Sequoia two hours apart. The first car travelled at 30 mph and the second car travelled at 40 mph. How long before both cars travelled the same distance>
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1st car DATA:
rate = 30 mph ; time = x hrs ; distance = 30x miles
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2nd car DATA:
rate = 40 mph ; time = x-2 hrs ; distance = 40x-80
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Equation::
distance = distance
30x = 40x - 80
10x = 80
x = 8 hrs (after 8 hrs the cars are the same distance from Sequoia.
Cheers,
Stan H.
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