This is a multiple part problem but I'd like to have some help on one part at a time. Here is the general question: A pulley with a radius of R=0.50m and a mass of M=4.0kg is mounted on a frictionless axle. The pulley is a uniform solid disk with a rotational inertia of I=1/2MR^2. A block with a mass m=2.0kg hangs from a string wrapped around the pulley. When the system is released from rest the block accelerates down. Use g=10m/s^2. a) After dropping through a height h, the block's speed is 2.0m/s. Use energy conservation to find h. b)Apply Newton's Second Law, and Newton's Second Law for Rotation. Solve your equations to find the acceleration of the block. c)Use your value from (b) and one or more constant acceleration equations to find h, the distance the block has dropped when its speed reaches 2.0m/s. Does it agree with your answer from (a)? So for part (a)... the energy is KE + PE so it is 1/2Iw^2 + mgh which is...1/2(1/2(4.0kg)(0.50m)^2)0^2 + (2.0kg)(10m/s^2)h the final energy is 1/2(2.0kg)(2.0m/s)^2 + (2.0kg)(10m/s^2)(0m) so setting them equal to each other you get... 20h=4 so h=4/20, simplified is h=1/5 Is that right? If not please give me some hints, and I will work on part (b). Thanks!