Calculate String Tension with Simple Physics Math Help - No Quotation Marks

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The discussion revolves around calculating the tension in a string using physics equations. The user initially sets up two equations involving tension (T), mass (m), radius (r), and velocity (v) but struggles to solve for T. After realizing the known values for r and m, they consider substituting these into the equations. A suggestion is made to combine the equations to eliminate T and solve for v first, which could simplify the process. The user expresses understanding of this approach, indicating progress in solving the problem.
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What is the tension in the string?

okay i have figured this much out,

Tsin(16.69) = m (v^2)/ r
T cos 16.69 -mg =0

i don't know how to solve for T though. i know it should be simple math, but i can't figure it out!


i have tried this

r(tsin 16.69) / v^2 = m
and Tcos16.69 / g = m

and then make them equal,

Tcos16.69 / g = r(Tsin16.69)/V^2

but now i am lost
 
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klm said:
What is the tension in the string?

okay i have figured this much out,

Tsin(16.69) = m (v^2)/ r
T cos 16.69 -mg =0
What are the knowns and unknowns?
 
What values out of those you have written down do you know? At the moment you have two equations in four unknowns, so you will not be able to solve them!
 
oh sorry! i know that r=.3 and m =.2

but i just realized that if i know those, i can just plug them into the 2nd equation and find T...i think
 
klm said:
Tsin(16.69) = m (v^2)/ r
T cos 16.69 -mg =0
What I would do is immediately combine these equations to eliminate T and solve for v. Then you can plug in that answer for T.

(If you write the second equation as T cos 16.69 = mg, it might be easier to see how to combine them.)
 
^ooh i understand what you are saying. thank you!
 
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