Question 812254: A plane leaves Chicago and flies 750 miles to New York. If it takes 2.5 hours to get to New York flying against wind, but only 2 hours to fly back to Chicago, what is the plane's rate of speed?
I absolutely do not know how to do rate, distance, and time, so this problem makes no sense to me whatsoever. Therefore, I can't quite think of any equations to help solve this problem.
Thanks for your time!(:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! You can make your life a lot easier if you learn these three simple formulas
Dist = speed * time
d = s*t
:
Speed = dist/time
s = d/t
;
Time = dist/speed
t = d/s
:
A plane leaves Chicago and flies 750 miles to New York.
If it takes 2.5 hours to get to New York flying against wind,
but only 2 hours to fly back to Chicago,
what is the plane's rate of speed?
:
let s = speed of the plane in still air
let w = the speed of the wind
then
(s-w) = ground speed against the wind
(s+w) = ground speed with the wind
:
Write a distance equation for each way
2.5(s-w) = 750
2(s+w) = 750
Simplify both equation, divide the first by 2.5, the 2nd by 2
s - w = 300
s + w = 375
---------------adding eliminates w, find s
2s = 675
s = 337.5 mph planes speed in still air
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