Question

Mike COD Meteorology .. Tropical Tidbits Gmail Twitter Apps hysics Course Home <Homework-7 Practice Problem 9.9 In this example we will apply conservation of energy to a simplified version of a yo-yo. We will need to account for the fact that the yo-yo has both translational and rotational kinetic energies as it unwinds from the string. (Figure 1) shows our primitive (and not very practical) yo-yo in the form of a solid disk with radius Rrand total mass M. It is released from rest, the supporting hand is stationary, and the string unwinds without slipping. Find an expression for the sneed. m.of the CS: Figure K 1 of 1 > R М h f Ves 3

Answer 1

According to the condition given potential energy 50 pe; = 0; = mgh. 40. Kinetic Energy Conſtial) = 0. kef= 2 M Vem + 1 limo? The work done by non conservative forces is zero and total energy is conserved 1. Ki tu; = kft uf from Conservation of energy - ot mgh = 1 Venta + 1 lem to. Both "cm and w are unknown. But if we assume that string unwinds without slipping - Vom = Rw Icm = 4 mR & Mgh + merem + 1 Me") ( Nem) ? 3 mm