For the two systems shown in Figure 3, (i) Draw the free body diagrams for the disk rolling without slipping, the pulley and the vertical mass in

 For the two systems shown in Figure 3,

(i) Draw the free body diagrams for the disk rolling without slipping, the pulley and the vertical mass in Figure 3a; 

(ii)If a vertical spring is added into the system as shown in Figure 3b, Will the equation of motion and the natural frequency be changed? Why?