What is the horizontal distance between the two airplanes at 1:00pm? An airplane flying west at 400 km/h goes over another airplane flying south...

First we will calculate the distance each airplane travels
by 1:00 pm.

The first
plane:

Travels west with speed (s1) = 400 at 11:00
am

Then the time by 1:00 pm is T1 = 2
hours.

Then, we know that the distance (D) is given by the
formula:

D = S*T

==> D
1= 400*2 = 800 km ...........(1)

The second
airplane:

Given that the speed is S2 =
500

Then time is also 2 hours ==> T2=
2

==> D2 = T2* S2 = 500*2 = 1000
km.............(2)

Now we need to find the distance between
them at 1:00.

The planes travels in two perpendicular
paths.

Then, the distance between them is the hypotenuse of
a right angle triangle.

==> D^2 = D1^2 + D2^2 =
(800)^2 + (1000)^2 = 1,640,000

==> D = 1280.62
km

Then, the distance between the planes by
1:00pm is 1280.62 km.