Question 225880: I need help with this problem:
With a certain tail wind a certain jet aircraft arrives at it's destination, 1,890 miles away,in 3 hours. Flying against the same wind, the plane makes the return trip in 3 3/8 hours. Find the wind speed and the plane's airspeed.
thank's
Destiny
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! With a certain tail wind a certain jet aircraft arrives at it's destination, 1,890 miles away,in 3 hours.
Flying against the same wind, the plane makes the return trip in 3 3/8 hours.
Find the wind speed and the plane's airspeed.
:
Let s = speed of the plane in still air
Let w = speed of the wind
then
(s-w) = plane speed against the wind
and
(s+w) = plane speed with the wind
:
Change 3 3/8 hrs to 3.375 hrs
:
The trips there and back are equal distance, (1890 mi) write two distance equations
dist = time * speed
:
3.375(s-w) = 1890
3.0(s + w) = 1890
:
It is convenient that we can simplify both these equations:
divide the 1st by 3.375
divide the 2nd by 3
resulting in two simple equations that can be used for elimination of w
s - w = 560
s + w = 630
----------------adding eliminates w, find s
2s = 1190
s = 
s = 595 mph is the plane speed in still air
Find w
595 + w = 630
w = 630 - 595
w = 35 mph is the wind speed
:
:
You can check these solutions using the 1st two equations with these values
|
|
|
