SOLUTION: Two cars heading in same direction, 300 ft apart. One behind is traveling 53 mph, one in front is traveling 40 mph. How many seconds until they hit? What if the front one is tra

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Question 429287: Two cars heading in same direction, 300 ft apart. One behind is traveling 53 mph, one in front is traveling 40 mph. How many seconds until they hit? What if the front one is traveling 10 mph?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let d = distance front car has to go
Let t = time for them to meet
equation for 40 mi/hr car
(1) d+=+40t
equation for 53 mi/hr car
(2) d+%2B+300%2F5280+=+53t+
Substitute (1) into (2)
(2) 40t+%2B+300%2F5280+=+53t+
+13t+=+300%2F5280+
+t+=+.0568%2F13+
+t+=+.00437+ hrs
+t+=+.00437+%2A+60%2A60+=+15.73+ hrs x min/hr x sec/min
They hit in 15.73 sec
--------------------------
If the front car goes 10 mi/hr
(1) +d+=+10t+
(2) d+%2B+300%2F5280+=+53t+
(2) 10t+%2B+300%2F5280+=+53t+
+43t+=+.0568+
+t+=+.00132+ hrs
+t+=+.00132+%2A+60+%2A+60+=+4.757+ sec
They hit in 4.757 sec