d = rt Word problem: distance between planes going N, W

[DC6]

:? Hi again:

I thought I understood this one, but i kept getting the wrong answer

If 2 planes leave the same airport at 1 pm, how many miles apart will they be at 3 pm if one travels directly north at 150 mph and the other travels directly west at 200 mph.

So I solved for the d for the plane going north, which was Dn = 150 mph(2h) = 300 miles and the plane going west was Dw = 200 mph(2h) = 400 miles

To get the distance between the two I set it up like a right triangle and and used the equations D = 1/2(Dn)(Dw). I got 60,000 miles, WHICH IS WRONG!!!

DC6

 

[stapel]

If 2 planes leave the same airport at 1 pm, how many miles apart will they be at 3 pm if one travels directly north at 150 mph and the other travels directly west at 200 mph.

What is the time each has flown? So what is the distance that each has flown?

To get the distance between the two I set it up like a right triangle and and used the equations D = 1/2(Dn)(Dw).

This almost looks like you're trying to find the area of the triangle...? :shock:

You have a right triangle, with the lengths of two sides known. You are asked for the length of the third side, being the distance between the two planes. Perhaps the Pythagorean Theorem might help...? :wink:

Eliz.

 

[DC6]

with

a^2 + b^2 = c^2

I get an answer of 30,000 miles... not the right answer. it should be 500

 

[stapel]

with a^2 + b^2 = c^2 I get an answer of 30,000 miles... not the right answer. it should be 500

It might help if you showed your work. We can't check for errors that we can't see (and I can't guess how you solved "a[sup:26oq4swz]2[/sup:26oq4swz] + b[sup:26oq4swz]2[/sup:26oq4swz] = c[sup:26oq4swz]2[/sup:26oq4swz]" for "c =" and got "30,000", given the input values for "a" and "b").

Please be complete. Thank you!

Eliz.

 

[DC6]

My work:

Dn= a = 150 mph(2hr) = 300 miles
Dw = b = 200 mph (2hr) = 400 miles

a^2 + b^2 = c^2
300^2 + 400^2 = c^2
c = sqrt (90000+160000)
c = sqrt(250000)
c = 500

Nevermind: I answered my own questions. Just doing the calculation wrong. :roll:
Bear with me, I haven't done this kind of math since 1997. I am studying for the PCAT (test for pharmacy school (PharmD)).