Question

Determine from your textbook or the Internet the equation for the rotational inertia I of a solid uniform
disc of radius R, thickness h and mass M. You will use this expression to calculate the theoretical I for
the disc used in this experiment. I was thinking I=mr^2?

Answer 1

I = MR^2
should be right for a thin-walled hollow cylinder (think canned items). A hollow cylinder where the inner radius is small is I = 1/2 M(Inner Radius^2 + Outer Radius^2)

Answer 2

what does is meant by solid uniform?

Answer 3

@wastetime

Answer 4

@Sukhvir Solid uniform means entirely solid, no holes or gaps which would make the disk a cylinder with no holes. Uniform states that the solid is the same density throughout the solid.

Answer 5

@wastetime ok so why am i able to use I=mr^2 then?

Answer 6

@Sukhvir I think I mistakenly wrote the wrong thing in my first post. I=MR^2 is the moment of inertia of a cylinder and a disk because a disk is a very thin cylinder.

Answer 7

@wastetime Oh ok, so what is the formula of rotational interia that i would use for this type of question?

Answer 8

I=mr^2/4?

Answer 9

I=MR^2 should be right

Answer 10

ok thanks @wastetime