Ask Remember Me?
 rpmacs Posts: 11, Reputation: 2 New Member #1 Nov 22, 2009, 09:04 AM
Jet speed against the wind
A jet takes the same time to travel 2500 km %.555 with the wind as it does to travel 1900 km 2.555against the wind. If its speed relative to the air is 450 km/hr, what is the speed of the wind?

I came up with a wind speed of 3 Km/hr
Not sure how to put in a formula.
 galactus Posts: 2,271, Reputation: 282 Ultra Member #2 Nov 22, 2009, 09:20 AM
What is the %.555 and the 2.555?

The problem says, "in the same amount of time". That is a clue to equate the times.

When the plane is flying with the wind, it is being helped along. So, we add the rate of the wind to the rate of the plane.

Likewise, when it is flying against the wind it is being held back. So, we subtract the rates.

This is just d=rt. Then, t=d/r

$\frac{2500}{450+w}=\frac{1900}{450-w}$

Solve for w, the speed of the wind. The wind blows stronger up there where the plane is than down here on the ground.

It is faster than 3 kph. Unless I am missing something. I am confused by the %.555 and 2.555.
 rpmacs Posts: 11, Reputation: 2 New Member #3 Nov 22, 2009, 11:07 AM

I came up with:-

2500w+2500*450=1900w+1900*450

-4400w=-270000

w=61.36

Not your question?

 Question Tools Search this Question Search this Question: Advanced Search

## Check out some similar questions!

I wonder what's wrong? It's a wonderful antique. Looks not too different to this: Sunbeam Mixmaster Stand Mixer : Target It has a variable speed control. All of a sudden it no longer responds to the speed dial but runs top speed constantly. What is wrong and how might I go about fixing...

Wind Loads on Beach Houses at wind speeds of 130mph [ 4 Answers ]

How to I find the wind load for speeds at 130 mph?

I have a 1965 and 1970 jet magazine they're in perfect condition how much are they worth

Home Well Jet Pump Mystery. [ 14 Answers ]

Hey all! I have been having these water problems lately and can't seem to figure it out. It seems that after this second pressure switch I bought, the lead connections and wires melt so that they can not reach far enough to connect. I have had 2 people come out and replace the pressure switch,...

The calm wind runway when the wind velocity is