I need help with the following question from math(A private plane took 2h to make a 600 km trip when flying the wind. The return trip, flying against the same wind, took 2.5 h. Find the wind speed and the plain's air speed.) Thank You very much for all the help I receive from everyone. I greatly appreciate it.
2007-05-27 04:02:31 · 5 answers · asked by crobabe2182 1 in Science & Mathematics ➔ Mathematics
You need a variable for the plane's speed in still air (p) and the wind speed (w). The basic formula is distance = speed times time. So you'd have
600 = (p + w) 2
600 = (p - w) 2.5
THese become
600 = 2p + 2w
600 = 2.5p - 2.5w
If you multiply the first equation by 2.5 and the second by 2, you can eliminate the w thereby solving for p. Then plug this value in to either equation to find w.
2007-05-27 04:13:47 · answer #1 · answered by hayharbr 7 · 1⤊ 0⤋
Let speed of plane = x mph
Downwind
Time: 2h
Distance : 600 km
Speed: (x + y) km/h
x + y = 600 / 2
x + y = 300
Upwind
Time: 2.5 h
Distance: 600km
Speed: x - y km/h
x - y = 600 / 2.5
x - y = 1200 / 5
x - y = 240
x - y = 240
x + y = 300-----ADD
2x = 540
x = 270
y = 30
Plane speed = 240 km / h
Wind speed = 30 km / h
2007-05-27 09:58:03 · answer #2 · answered by Como 7 · 0⤊ 0⤋
If a = air speed and w = wind speed in km/h
2(a + w) = 600
2.5(a – w) = 600
a + w = 300
a – w = 240
2a = 540
a = 270 km/h
w = 300 – 270 = 30 km/h
2007-05-27 04:17:51 · answer #3 · answered by rrabbit 4 · 0⤊ 1⤋
x-wind speed, y - plane speed
(x+y)*2h=600km
(y-x)*2.5h=600km
x+y=300
y-x=240
you should be able to take it from here.
2007-05-27 04:09:43 · answer #4 · answered by Regal 3 · 0⤊ 1⤋
should the rotation of the earth also be taking into account ?
2007-05-27 04:06:23 · answer #5 · answered by gjmb1960 7 · 0⤊ 1⤋