 #1
 121
 0
Homework Statement
hi again ,, help me to get moment of inertia
A solid sphere, of mass 1.5 kg and radius 5 cm, is connected to the end of a vertical rod
along a y–axis, of mass 2 kg and length 35 cm. The rod can rotate about z–axis passing
through the other end, as show in the figure.
a) What is the moment of inertia of the system (sphere + rod) about z–axis?
b) Starting from rest, the system rotates clockwise around the z–axis from the initial
vertical orientation, what is its angular speed when it is inverted?
Homework Equations
The moment of inertia about the center of mass:
Irod = ML^2/12 and Isphere = (2/5)mR^2
The Attempt at a Solution
i tried to solve (I still don't how to get moment of inertia yet) like this :
I=Irod + m(L/2)^2 + (2/5)mR^2+m(LR)^2 = (1/3)ML^2+(7/5)mR^2 is it right ??
Attachments

36.8 KB Views: 265