How do I do this physics problem?

A 1.57-gram airplane is attached to a string with a length of 1.32 meters. The plane flies in a circle in which the string is declined at an angle (Theta) of 31.7 degrees below the horizontal. At what speed (in m/s) is the plane flying?

Question

How do I do this physics problem?

A 1.57-gram airplane is attached to a string with a length of 1.32 meters. The plane flies in a circle in which the string is declined at an angle (Theta) of 31.7 degrees below the horizontal. At what speed (in m/s) is the plane flying?

radames321 · Answer

ya he did and knows the answer but he wants to know how herman got the answer

harman.singh · Answer

There's this document which explains it step by step. Maybe have a read of it and if you need help understanding specific parts of it, I can explain. https://brainmass.com/file/51097/60614.doc

steve816 · Answer

Is it possible for you to copy paste this? I don't wanna click on that to download it lol

harman.singh · Answer

Here you go :)
|dw:1481857128873:dw|

steve816 · Answer

Thank you so much harman

harman.singh · Answer

No worries :-)

steve816 · Answer

@yellowfellow007

steve816 · Answer

FML, I still don't get this -_-

johnweldon1993 · Answer

What are you still getting messed up on?

steve816 · Answer

Ok I will write out my thought process, please bare with me.

steve816 · Answer

So first, I drew the free body diagram with the triangle like this;

steve816 · Answer

|dw:1481858962227:dw|
Ok, so I knew that mg = 0.00157 * 9.8 = 0.015386
I knew that $$\large F _{net}=0.015386\cot(31.7 °)$$ Then I solved for the velocity like this:$$\large \frac{ mv^2 }{ r }=F _{_{net}}$$$$\large \frac{ 0.00157*v^2 }{ 1.32}=0.02491$$I solve for v and I get $$\large v = 4.5766$$The answer is supposed to be 4.22, please help.