1. The problem statement, all variables and given/known data A 0.020-kg mass is attached to a 1.2-m string and moves in a horizontal circle with a constant speed of 1.50 m/s, as shown in the figure. What is the measure of angle θ? What is given: m = 0.020kg v = 1.50 m/s L = 1.2 m 2. Relevant equations Lengths L = 1.2m Lsinθ = r Forces: Tx = Tsinθ = Fc Ty = Tcosθ T = mg/cosθ 3. The attempt at a solution What would solve this: atan(Fc/mg) – (Fc needs r) atan(r/h) –(r is unknown, and h would require knowing θ or r) One (of the many) attempted solutions: T = mg/cosθ Fc = Tsinθ Fc = mg/cosθ * sinθ Fc = mg*sinθ/cosθ Fc = mv2/r mv2/r = mg*sinθ/cosθ r is unknown, but r = Lsinθ mv2/Lsinθ = mg*sinθ/cosθ mv2/L = mg*sin2θ/cosθ mv2/mgL = sin2θ/cosθ v2/gL = sin2θ/cosθ My problem continually being the sin2θ/cosθ, making that not tanθ. If there's something I missed, I feel like it might be some trig identity or sloppy algebra? Nothing came to mind immediately. Every solution path I went, I always ended up needing θ or 'r'. Would really appreciate some help with this one, as I've been consuming too much time with this single scenario. Thank you!