1. A solid sphere has a radius of 0.200 m and a mass of 150 kg. How much work is required to get the sphere rolling with an angular speed of 50.0 rad/s on a horizontal surface? Assume the sphere starts from rest and rolls without slipping 2. The attempt at a solution I found V first. V= rw = 0.2 x 50 =10 m/s Then Fc Fc = mv^2/r = (150)(10)^2 / 0.2 =75000 N W= F X R = 75000 x 0.2 = 15000 J The answer the teacher gave was 1.05 x 10^4 J or 10500 J... What did I do wrong? Thank you for your help!