How Fast Should Devita Release the Kite String?

[stressedgirl]

Homework Statement

Devita is standing still teachnig Matthew about flying a kite. The kite is already 15 m high and she has let 25 m of string. It is now being blown directly away from her at a constant height with a horizontal velocity of 2.0 m/s. At what rate must Devita be letting out the string?

The Attempt at a Solution

Ok so first I drew vector components for the displacement. You get an angle using sin(15/25) = 36.9 deg.

Then I drew a diagram like so:
[URL]http://img819.imageshack.us/i/diagrm33.png/[/URL]

I calculated for the VAvg and got VAvg = 2.5 m/s, but my teacher says it is supposed to be 1.6. Ideas??

 

[gneill]

Ok so first I drew vector components for the displacement. You get an angle using sin(15/25) = 36.9 deg.

Then I drew a diagram like so:
[URL]http://img819.imageshack.us/i/diagrm33.png/[/URL]

I calculated for the VAvg and got VAvg = 2.5 m/s, but my teacher says it is supposed to be 1.6. Ideas??

Sure! Plenty of ideas!

First though, your image link didn't show up in your post, possibly because it wasn't associated with some text string. http://img819.imageshack.us/i/diagrm33.png/"

Perhaps you could show the details of your calculation, and describe why it should yield the rate of string release.