1. The problem statement, all variables and given/known data 15. A solid sphere of mass 6.0 kg is mounted on a vertical axis and can rotate freely without friction. A massless cord is wrapped around the middle of the sphere and passes over a 1.0 kg pulley and is attached to block of mass 4.0 kg, as shown. What is the speed of the block after it has fallen 80 cm? Treat the pulley as solid cylinder. 2. Relevant equations E initial = E after ωp = angular velocity of pulley ωs = angular velocity of sphere rp = radius of pulley rs = radius of sphere Forces ------- Pulley: Iα = Rp(T2-T1) (rp^2/2)(a/rp) = Rp(T2-T1) =(a)/2 = T2-T1 Block: mg-T2 = ma =39.2 - T2 = 4a Sphere: Iα = Rs(T1) T1 = (2/5)(6)(rs)^2 T1= 2a/5 a = 8m/s^2 T2=7.2N T1=3.2N v^2-v0^2 = 2ad v0 = 0 v^2 = 2(8)(.8) v=3.57m/s So initially I thought energy would be used in this situation, but now I'm trying to think if it's even necessary.