5 replies to this topic

[Mr. Hobo]

We're doing vectors and what I'm missing is one method of solving them.

It looks like the vectors get broken down into their components and then solved mathematically but I'm trying to remember everything from glancing at someone's homework so I might fail at explaining it

ex. You are a pilot on an aircraft carrier. You must fly to another aircraft carrier, now 1450 km at 45 degrees of your position, moving at 56 km/h die east. The wind is blowing from the south at 72km/h. Calculate the heading and air speed needed to reach the carrier 2.5h after you take off

And what you have to do is solve it and then break down the vectors in terms of north/south (y) and east/west (x).

How would you do that? If I didn't explain the breaking down of the vectors just showing me how to do the problem would be tres helpful

Thanks

xoxoxoxox

[Warriors]

Isn't it just drawing a vector diagram? its the difference between ground speed and airspeed which is caused by the influence of the winds on the overall velocity of the aircraft

ground speed = airspeed + wind speed. The word "speed" really should be "velocity" as I suspect you realize. So, airspeed = ground speed - windspeed.

Va = Vg - Vw


I think that's how it goes..Might want to double check that. I don't know that much of HS physics according to my grade, C...lol all the time me and friends would play advance wars during class...

Edited by Warriors, 26 January 2011 - 10:37 PM.

[Mr. Hobo]

I dunno man. I did some work on it and it got a lot more complex than what you did and I think I'm like halfway done. But my notebook is hiding from me and I'm tired so alas I can not post it

[Warriors]

I dunno man. I did some work on it and it got a lot more complex then what you did and I think I'm like halfway done

Haha, there ya go..

[Mr. Hobo]

Many thanks anyways

[Lallard]

I don't know exactly what you mean by "heading" but if "air speed" is interchangeable with "velocity" in this case it's just all about setting up a force-vector diagram:

You must fly to another aircraft carrier, now 1450 km at 45 degrees of your position, moving at 56 km/h die east

so if our origin is the pilot's position, define the position of the aircraft carrier at: x0 = 1450cos(45)i + 1450sin(45)j.
Also set the target carrier to be traveling at v(t)=+56ti with t as time in hours.

The wind is blowing from the south at 72km/h.

assign that as vwind (t) = -72tj.

needed to reach the carrier 2.5h after you take off

So in t = 2.5, assuming that your target aircraft carrier is also affected by the wind blowing southward we add x0 with v(2.5) and vwind(2.5) in order to determine the overall distance by the target carrier from the point of origin (our pilot from point 0);

= 1450cos(45)i + 1450sin(45)j + 56(2.5)i - 72(2.5)j

then whatever your resulting vector is you divide that by 2.5 hours and you should get your velocity needed to catch up to your target.


EDIT: I'll wait for you to update me on what those two things specifically mean (since to be honest it might be some odd thing that requires more than just what I think may be all you need).

Edited by Lallard, 26 January 2011 - 11:42 PM.