SOLUTION: Two cities X and Y are connected by a highway. A car leaves city X at 12:00 noon at the constant speed of 55 mi/hr, traveling on the highway towards city Y. Twenty minutes later an
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-> SOLUTION: Two cities X and Y are connected by a highway. A car leaves city X at 12:00 noon at the constant speed of 55 mi/hr, traveling on the highway towards city Y. Twenty minutes later an
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Question 945811: Two cities X and Y are connected by a highway. A car leaves city X at 12:00 noon at the constant speed of 55 mi/hr, traveling on the highway towards city Y. Twenty minutes later another car leaves city X traveling towards city Y on the same highway as the first car, at the constant speed of 60 mi/hr. At what time will the second car reach the first car? (The lengths of the cars are disregarded.) Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! What is 1st car's head start? mi
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Start a stop watch when 2nd car
leaves. Let = time in hrs
on stop watch when 2nd car
catches the 1st car
Let = distance in miles 2nd
car travels until it catches 1st car
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1st car's equation:
(1)
2nd car's equation:
(2)
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Substitute (2) into (1)
(1)
(1)
(1)
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Add 20 minutes to this time
( converted to hrs )
2nd car reaches 1st car at:
12:00 noon + 4 hrs = 4:00 PM
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check:
(2)
(2)
(2)
and
(1)
(1)
(1)
(1)
OK