SOLUTION: Two cars leave town at the same time going in the same direction on the same toad. One travels 32 mi/h and the other travels 47 mi/h. In how many hours will they be 69 miles apar

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Question 188929: Two cars leave town at the same time going in the same direction on the same toad. One travels 32 mi/h and the other travels 47 mi/h. In how many hours will they be 69 miles apart?
Found 2 solutions by Alan3354, jojo14344:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Two cars leave town at the same time going in the same direction on the same toad. One travels 32 mi/h and the other travels 47 mi/h. In how many hours will they be 69 miles apart?
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Going the same direction, the speed of one relative to the other is the difference, 47-32 = 15 mph.
69/15 = 4.6 hours

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


Car[1] = Speed[1] = 32mi/hr
Car[2] = Speed[2] = 47mi/hr

Remember for Speed = Distance / time

And Distance = Speed*time (working Eqn)

We both cars will be apart by 69 miles in t (hours)

So we need to subtract their speed in relevance to the time when they're apart 69 miles
.

Putting into equation:
69mi=S%5B2%5D%2At+-+S%5B1%5D%2At
69=+47t+-+32t
69=15t -----> cross%2869%294.6%2Fcross%2815%29=cross%2815%29t%2Fcross%2815%29
t=4.6 hours or 4 hours and 36 minutes

Let's check:
D%5B1%5D=S%5B1%5D%2At=32%2A4.6=red%28147.2miles%29
D%5B2%5D=S%5B2%5D%2At=47%2A4.6=red%28216.2miles%29

Difference: D%5B2%5D-D%5B1%5D=216.2-147.2+=+highlight%2869miles%29

Thank you,
Jojo