SOLUTION: A car leaves Oak Corners at 11:30 AM traveling south at 60 mph. At the same time, another car is 50 miles west of Oak Corners traveling east at 40 mph. Express the distance d betwe

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Question 214875: A car leaves Oak Corners at 11:30 AM traveling south at 60 mph. At the same time, another car is 50 miles west of Oak Corners traveling east at 40 mph. Express the distance d between the cars as a function of the time t after the first car left Oak Corners.
Found 2 solutions by Alan3354, josmiceli:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A car leaves Oak Corners at 11:30 AM traveling south at 60 mph. At the same time, another car is 50 miles west of Oak Corners traveling east at 40 mph. Express the distance d between the cars as a function of the time t after the first car left Oak Corners.
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It's not clear which is the "1st car", but starting from the time one car is 50 miles west (1130):
d^2 = (50 - 40t)^2 + (60t)^2
d^2 = 2500 - 4000t + 1600t^2 + 3600t^2
d^2 = 5200t^2 - 4000t + 2500
d(t) = 10sqrt(52t^2 - 40t + 25) t in hours, d in miles

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The car going south has d%5B1%5D+=+60t mi From Oak Corners
where t is in hours and d is in miles
The car going east is d%5B2%5D+=+50+-+40t mi from Oak Corners
The distance between the cars is:
d%5E2+=+%2860t%29%5E2+%2B+%2850+-+40t%29%5E2
d%5E2+=+3600t%5E2+%2B+2500+-+4000t+%2B+1600t%5E2
d%5E2+=+5200t%5E2+-+4000t+%2B+2500
d+=+sqrt%285200t%5E2+-+4000t+%2B+2500%29 answer
check:
In 3 hrs, the car going south has gone:
d%5B1%5D+=+60%2A3
d%5B1%5D+=+180 mi
In 3 hrs the car going east is
d%5B2%5D+=+50+-+40%2A3
d%5B2%5D+=+-70 mi from Oak Corners (It's East of it)
d+=+sqrt%28180%5E2+%2B+70%5E2%29
d+=+sqrt%2832400+%2B+4900%29
d+=+sqrt%2837300%29
d+=+193.132 mi
and
d+=+sqrt%285200t%5E2+-+4000t+%2B+2500%29
d+=+sqrt%285200%2A3%5E2+-+4000%2A3+%2B+2500%29
d+=+sqrt%2846800+-+12000+%2B+2500%29
d+=+sqrt%2846800+-+9500%29
d+=+sqrt%2837300%29
d+=+193.132
OK