# I A more direct approach in determining moment of inertia?

1. Nov 17, 2016

### bluejay27

is there a directly knowing the moment if the moment of inertia would be lower for an object? I am emphasizing on knowing the value of the constant value. For a sphere is 2/5 and for a cylinder 1/2, this constant values will be placed at c of cMR^2 without directly going into calculus. A mnemonic perhaps?

2. Nov 17, 2016

### BvU

I take it you know the definition of $I$, the moment of inertia ? The closer the massive stuff is to the axis, the lower $I$. And that's about it. You can go through the list and conclude for yourself there's no tricks or mnemonics.
The parallel axis theorem can be useful to translate to another (parallel) axis.