# Modelling a cylinder [closed]

I am fairly new to Mathematica.

I am trying to model an ideal cylinder of uniform density of radius R (any arbitrary value) which has a cylinder of radius R/2 missing from it. The resulting solid is rolling in a straight line. The centre of mass is calculated to be R/6 from the point equidistance to the circumference of the larger circle.

How do I go about doing this? And how would I be able to show a graph of angular rotation between the line perpendicular to the x-axis and the line of symmetry of this system?

• I don't suppose this is a homework question...is it? You'll usually get more 'bites' if you also post code you tried yourself...and then show us where your attempt failed...but this is a fairly standard mechanics question, with even an equation of motion with an analytical solution...finding the equation and looking at the docuemntation for DSolve will get you pretty far. – morbo Jun 12 '19 at 21:46
• A well-labeled diagram of the system would be helpful. – m_goldberg Jun 13 '19 at 2:29

Here's how you begin:

    RegionPlot3D[
y^2 + z^2 < 4 &&
-2 < x < 2 &&
y^2 + (z - .5)^2 > .5,
{x, -3, 3},
{y, -3, 3},
{z, -3, 3},
PlotPoints -> 100,
PlotStyle -> Opacity[0.5]]