SOLUTION: a car leaves town at 30 mph, tow hours later another car leaves same place, going the same direction at a speed of 42 mph. How many hours will the second car be driven before it ca
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Question 676175: a car leaves town at 30 mph, tow hours later another car leaves same place, going the same direction at a speed of 42 mph. How many hours will the second car be driven before it catches up?
After two hours, the first car will have travelled 60 miles (2h times 30 mph). The second car is going 12 mph faster. How long does it take to go 60 miles at 12 mph?
John
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it
You can put this solution on YOUR website! How much of a head start does the 1st car get? mi
Now start a stop watch when the 2nd car leaves
Let = time on stopwatch when 2nd car catches first car
Let = distance 2nd car travels until it catches 1st car = distance 1st car travels
-------------------
Equation for 1st car:
(1)
Equation for 2nd car:
(2)
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Substitute (2) into (1)
(1)
(1)
(1)
The 2nd car catches the 1st car in 5 hrs
check:
(2)
(2)
(2)
and
(1)
(1)
(1)
(1)
OK
