1. The problem statement, all variables and given/known data A small metallic bob is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal circle so that the thread describes a cone. Given: Length of string = 2.8m Angle between string and vertical: 21 degrees Mass of bob: 2.9kg 2. Relevant equations I = mr^2 w = square root of [g/(lcos(theta)] Momentum = I x w 3. The attempt at a solution I first calculated the angular velocity by plugging numerical values into the equation and got 1.936 rad/s. Then, I found out the moment of inertia of the bob by multiplying 2.9 x 2.8^2 [this is the step I'm not sure of], but the answer wasn't right. Is there something I missed out? Thank you for your help!