SOLUTION: N5145 is chasing N5455. N5145 is traveling at 240 mph and N5455 is traveling at 180 mph. If they are 10 miles apart, when will closure occur? (in minutes)

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Question 1031965: N5145 is chasing N5455. N5145 is traveling at 240 mph and N5455 is traveling at 180 mph. If they are 10 miles apart, when will closure occur? (in minutes)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +d+ = the distance in miles that faster one
has to travel until it catches slower one
+d+-+10+ = the distance in miles that slower one
has to travel until it is caught
Let +t+ = time in hrs for faster one to catch slower one
--------------------------------------------------
Equation for faster one:
(1) +d+=+240t+
Equation for slower one:
(2) +d+-+10+=+180t+
---------------------
Substitute (1) into (2)
(2) +240t+-+10+=+180t+
(2) +60t+=+10+
(2) +t+=+1%2F6+ hr
Convert to minutes
+%281%2F6%29%2A60+=+10+
Closure occurs in 10 min
-----------------------
check:
(1) +d+=+240%2A%281%2F6%29+
(1) +d+=+40+
and
(2) +d+-+10+=+180%2A%281%2F6%29+
(2) +d+-+10+=+30+
(2) +d+=+40+
OK