SOLUTION: A jet airplne leaves an airport traveling at a steady rate of 600km/h. Another jet leaves the same airport 3/4 h later traveling 800km/h in the same direction. How long will the

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Question 561662: A jet airplne leaves an airport traveling at a steady rate of 600km/h. Another jet leaves the same airport 3/4 h later traveling 800km/h in the same direction. How long will the second jet take to overtake the first?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
How many km head start does the 1st plane have?
+d%5B1%5D+=+600%2A%283%2F4%29+
+d%5B1%5D+=+450+
Let +t+ = time for 2nd jet to overtake 1st
Let +d+ = distance that 2nd jet travels
-----------------
Equation for 2nd jet:
(1) +d+=+800t+
Equation for 1st jet:
(2) +d+-+450+=+600t+
( note that t is the same for both )
Substitute (1) into (2)
(2) +800t+-+450+=+600t+
(2) +200t+=+450+
(2) +t+=+2.25+
It will take the 2nd jet 2 hrs and 15 min to overtake 1st
check answer:
(1) +d+=+800%2A2.25+
(1) +d+=+1800+ km
and
(2) +d+-+450+=+600%2A2.25+
(2) +d+=+1350+%2B+450+
(2) +d+=+1800+ km
OK