A yo-yo is made of two solid cylindrical disks, each of mass 0.049kg and diameter 0.074m , joined by a (concentric) thin solid cylindrical hub of mass 0.0053kg and diameter 0.010m . Use conservation of energy to calculate the linear speed of the yo-yo when it reaches the end of its 0.90m long string, if it is released from rest in m/s. What fraction of its kinetic energy is rotational?