Calculating the moment of inertia for this configuration

[Demon117]

Homework Statement

I need to find the rotational kinetic energy of this system in the figure I have provided. Here the spring is rotating with the system at angular speed $\omega$. The two beads on the wire move vertically, and the third bead is held by two massless rods of equal length L.

The Attempt at a Solution

Would the moment of inertia for the the whole thing just be

$I_{1,3}=2mL^{2}$

$I_{2,3}=2mL^{2}$

$I_{total}=4mL^{2}$

Any suggestions would be helpful.

 

[SammyS]

Homework Statement

I need to find the rotational kinetic energy of this system in the figure I have provided. Here the spring is rotating with the system at angular speed $\omega$. The two beads on the wire move vertically, and the third bead is held by two massless rods of equal length L.

The Attempt at a Solution

Would the moment of inertia for the the whole thing just be

$I_{1,3}=2mL^{2}$

$I_{2,3}=2mL^{2}$

$I_{total}=4mL^{2}$

Any suggestions would be helpful.

It looks as though the system is constrained to rotate about the z-axis.

You need to find the moment of inertia about the z-axis.

 

[Demon117]

Will it depend on the angle $\alpha$?

 

[SammyS]

Will it depend on the angle $\alpha$?

Yes it will depend on α .