How to Solve for CosA and T in a Conical Pendulum?

AI Thread Summary
To solve for CosA and T in a conical pendulum, the equations tcosA = mg and tsinA = mv^2/R are established, with R defined as LsinA. By substituting R into the second equation, T can be simplified. The relationship sin^2A + cos^2A = 1 allows for the elimination of sinA to express CosA in terms of T and other variables. The discussion concludes with the realization that this leads to a second-order equation.
sAXIn
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Hello all , I encouter a problem solving this one :

We are given a conical pendulum with : V - tan. speed of particle
m - mass of rotating particle
g - gravity acceleration
L - leght of the string

We need to find CosA , T by what is given above !
A- is the angle between the string and vertical line !

So : I wrote : tcosA=mg
tsinA=mv^2/R
R=LsinA

but I can't present cosA without sinA or something
Please Help !
 
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sAXIn said:
So : I wrote : tcosA=mg
tsinA=mv^2/R
R=LsinA
That's fine. You can simplify and solve for T. Use the 3rd equation to eliminate R from the 2nd equation. Then realize that \sin^2\theta = 1 - \cos^2\theta.
 
okay got it I get 2nd order eq.
thanks a lot
 
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