Hello! Quick question here. So, I'm learning about inertia in class and a question came up and I just want to make sure I understand this correctly. So, is it possible to increase the moment of inertia of an object without changing its' mass?

Question

anonymous · Answer

I said no it isn't possible. Because if you want to increase moment of inertia, wouldn't you have to decrease the mass of the object?

anonymous · Answer

Because, isn't inertia all about being dependent on the mass in the first place?

anonymous · Answer

no thats the answer. your correct

anonymous · Answer

Thank you so much for that clarification!

anonymous · Answer

Moment of inertia can be changed by changing the distribution  of the mass i.e. the shape of the mass as well as by changing the mass it self. 

  a rod of mass m and length l  has a moment of inertia equal to

 (1/12)ml^2 

while a sphere of mass m and radius r has a moment of inertial 

 (2/5)mr^2

a ring of mass m and radius r has a moment of inertia o

mr^2