Review. A string is wound around a uniform disk of radius R and mass M. The disk is released from rest with the string vertical and its top end tied to a fixed bar (Fig. P10.78). Show that (a) the tension in the string is one third of the weight of the disk, (b) the magnitude of the acceleration of the center of mass is 2g/3, and (c) the speed of the center of mass is (4gh/3)1/2 after the disk has descended through distance h. (d) Verify your answer to part (c) using the energy approach.
One more entropy problem: o Two boxes, of unequal size, have different amounts of energy. The box on the left has two packets of energy, and can contain 9. The one on the right has 3 packets and can contain 6 o If one packet of energy moves from the 6 to the 9, what is the change in entropy for : o • The 9box o • The 6box o • The system as a whole If, after one packet is moved from 6 9, another is moved (so that now the 6box has only one packet), what is the change in entropy for: o • The 9box o • The 6box o • The system as a whole o What is the most likely final state Will you see this state every time How do the temper