The measurement of the moment of inertia of a smartphone using the internal MEMS gyro to record its angular velocity as it topples over from rest in a vertical position ϑ (0) ≈ 0 to a horizontal landing has been described by Kaps and Stallmach (see Fig. 1). The analysis of this experiment is presented in terms of the conservation of energy, with the implicit assumptions that the edge of the smartphone does not slip

1.
A.
Kaps
and
F.
Stallmach
, “
Tilting motion and the moment of inertia of the smartphone
,”
Phys. Teach.
58
,
216
217
(
March
2020
).
2.
Tad
McGeer
and
Leigh Hunt
Palmer
, “
Wobbling, toppling, and forces of contact
,”
Am. J. Phys.
57
,
1089
1098
(
Dec.
1989
).
3.
Leaf
Turner
and
Jane l.
Pratt
, “
Does a falling pencil levitate?
Quantum
8
,
22
25
(
March/April
1998
).
4.
Rod
Cross
, “
The fall and bounce of pencils and other elongated objects
,”
Am. J. Phys.
74
,
26
30
(
Jan.
2006
).
5.
Vitor
Oliveira
, “
Experiments with a falling rod
,”
Am. J. Phys.
84
,
113
117
(
Feb.
2016
).
6.
Peter F.
Hinrichsen
, “
The toppling of a uniform rectangular block
,”
Am. J. Phys.
89
,
1026
(
Nov.
2021
).
7.
Eugene I.
Butikov
, “
Oscillations of a simple pendulum with extremely large amplitudes
,”
Eur. J. Phys.
33
(
6
),
1555
1563
(
2012
).
8.
Rod
Cross
, “
The fall of an inclined rod
,”
Eur. J. Phys.
42
(
5
),
055005
(
2021
).
9.
Readers can view the appendices at TPT Online, http://dx.doi.org/10.1119/5.0061475, under the Supplemental tab.

Supplementary Material

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