Think about an equipment setup the same as in this lab: A cube of mass M=500g and side length 30mm is free to spin on an axis through the center of one face. A mass less pulley on this axis has a diameter of 2r=10mm. A weight of m=50g is hung from a string wrapped around the pulley. The assembly is released from rest. Ignore friction.
1. Discover the time to unwind L = 30cm of string. Hint: Find the angular acceleration then the time.
2. Discover the kinetic energy of the spinning block after the string unwinds, using energy methods.