File:RollingVsInertia.gif

RollingVsInertia.gif ‎(506 × 311 pixels, file size: 695 KB, MIME type: image/gif, looped, 74 frames)

Summary

Description
English: Cylinders with the same mass but different moments of inertia will roll down a flat surface at different accelerations, as they have to "convert" different amounts of potential energy into kinetic energy to achieve a given angular velocity.
Date
Source https://twitter.com/j_bertolotti/status/1225050271384002561
Author Jacopo Bertolotti
Permission
(Reusing this file)
https://twitter.com/j_bertolotti/status/1030470604418428929

Mathematica 11.0 code

s1[t_] := R1 \[Phi]1[t];
x1[t_] := x10 + s1[t] Cos[\[Alpha]] + R1 Sin[\[Alpha]];
y10 = Abs[x10] Tan[\[Alpha]];
y1[t_] := y10 - s1[t] Sin[\[Alpha]] + R1 Cos[\[Alpha]];
T1[t_] := 1/2 m1 (D[x1[t], t]^2 + D[y1[t], t]^2) + 1/2 I1 (D[\[Phi]1[t], t])^2;
V1[t_] := m1 g y1[t];
L = FullSimplify[T1[t] - V1[t]]
eq1 = FullSimplify[D[D[L, \[Phi]1'[t]], t] - D[L, \[Phi]1[t]]]

m1 = 1; R1 = 1; g = 1; \[Alpha] = \[Pi]/6; x10 = -20;
sol = Table[
   NDSolve[{(eq1 == 0) /. {I1 -> j}, \[Phi]1[0] == 0, \[Phi]1'[0] == 1}, {\[Phi]1[t]}, {t, 0, 20}], {j, 0, 5}];
dim = Dimensions[sol][[1]];
\[CapitalDelta] = 2;
p1 = Table[ Legended[Graphics3D[{
Gray, Polygon[{{0, \[CapitalDelta], 0}, {1.2*x10, \[CapitalDelta], 1.2 y10}, {1.2*x10, (dim + 1) \[CapitalDelta], 1.2 y10}, {0, (dim + 1) \[CapitalDelta], 0}}], Table[{Hue[j/dim], Cylinder[({{x1[t], \[CapitalDelta] j, y1[t]}, {x1[t], \[CapitalDelta] (j + 1), y1[t]}} /. sol[[j]]) /. {t -> \[Tau]}, R1]}, {j, 1, dim}]}, Boxed -> False],
    PointLegend[Table[Hue[j/dim], {j, 1, dim}] , Table[StringJoin["m=\!\(\*SubscriptBox[\(m\), \(0\)]\)   I=", ToString[j], "\!\(\*SubscriptBox[\(I\), \(0\)]\)"], {j, 1, dim}], LegendMarkerSize -> 20,      LabelStyle -> {FontFamily -> "Times"}]  ]
   , {\[Tau], 0, 7.3, 0.1}];
ListAnimate[p1]

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
Creative Commons CC-Zero This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

creator

some value

author name string: Jacopo Bertolotti
URL: https://commons.wikimedia.org/wiki/user:Berto
Wikimedia username: Berto

copyright status

copyrighted, dedicated to the public domain by copyright holder

copyright license

Creative Commons CC0 License

inception

5 February 2020

MIME type

image/gif

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current09:24, 6 February 2020506 × 311 (695 KB)BertoUser created page with UploadWizard
The following pages on the English Wikipedia use this file (pages on other projects are not listed):

Global file usage

The following other wikis use this file:

  • Usage on ar.wikipedia.org
    • عزم القصور الذاتي

Metadata

Retrieved from "https://en.wikipedia.org/wiki/File:RollingVsInertia.gif"