SOLUTION: Hello, My question is: "The H.M.S. Dreadnaught is 10 miles north of Montauk and steaming due north at 15 miles/hour, while the U.S.S. Mona Lisa is 70 miles east of Montauk and s

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Hello, My question is: "The H.M.S. Dreadnaught is 10 miles north of Montauk and steaming due north at 15 miles/hour, while the U.S.S. Mona Lisa is 70 miles east of Montauk and s      Log On

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Question 427046: Hello, My question is:
"The H.M.S. Dreadnaught is 10 miles north of Montauk and steaming due north at 15 miles/hour, while the U.S.S. Mona Lisa is 70 miles east of Montauk and steaming due east at an even 40 miles/hour. How fast is their distance apart increasing?"
I know that will be the sum of miles that they are
(10*15) + (70*40) = 2950
But, I don't the rest. I think it will be divided by something, but I don't know what. I'm stuck on that question. Can you please help me on that?
Thanks,
Cristian

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
"The H.M.S. Dreadnaught is 10 miles north of Montauk and steaming due north at 15 miles/hour, while the U.S.S. Mona Lisa is 70 miles east of Montauk and steaming due east at an even 40 miles/hour. How fast is their distance apart increasing?"
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I know that will be the sum of miles that they are
(10*15) + (70*40) = 2950
If you include units, you'll see a problem with that
10 miles * 15 miles/hour = 150 sq miles/hr ?? Not good.
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Their directions are 90º apart, so it's a right triangle.
r%5E2+=+15%5E2+%2B+40%5E2+=+1825
r = sqrt(1825) =~ 42.72 mph
r = the speed of one relative to the other.
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The distances have no effect on the relative speed.