This paper describes a simple procedure for the study of the cooling of a spherical body using a standard thermometer and a smartphone. Experiments making use of smartphone sensors have been described before, contributing to an improved teaching of classical mechanics, but rarely expand to thermodynamics. In this experiment, instead of using a smartphone camera to slow down a fast movement, we are using the device to speed up a slow process. For that we propose the use of the free app Framelapse to take periodic pictures (in the form of a time-lapse video) and then the free app VidAnalysis to track the position of the mercury inside the thermometer, thus effortlessly tracking the temperature of a cooling body (Fig. 1).

1.
J.
Chevrier
,
L.
Madani
,
S.
Ledenmat
, and
A.
Bsiesy
, “
Teaching classical mechanics using smartphones
,”
Phys. Teach.
51
,
376
(
Sept.
2013
).
2.
J.
Hall
, “
More smartphone acceleration
,”
Phys. Teach.
51
,
6
(
Jan.
2013
).
3.
M.
Monteiro
,
C.
Stari
,
C.
Cabeza
, and
A. C.
Marti
, “
The Atwood machine revisited using smartphones
,”
Phys. Teach.
53
,
373
374
(
Sept.
2015
).
4.
A.
Shakur
and
J.
Kraft
, “
Measurement of Coriolis acceleration with a smartphone
,”
Phys. Teach.
54
,
288
290
(
May
2016
).
5.
P.
Vogt
and
J.
Kuhn
, “
Analyzing simple pendulum phenomena with a smartphone acceleration sensor
,”
Phys. Teach.
50
,
439
(
Oct.
2012
).
6.
P.
Vogt
,
J.
Kuhn
, and
S.
Müller
, “
Experiments using cell phones in physics classroom education: The computer-aided g determination
,”
Phys. Teach.
49
,
383
384
(
Sept.
2011
).
7.
S.
Becker
,
P.
Klein
, and
J.
Kuhn
, “
Video analysis on tablet computers to investigate effects of air resistance
,”
Phys. Teach.
54
,
440
441
(
Oct.
2016
).
8.
S.
Gröber
,
P.
Klein
, and
J.
Kuhn
, “
Video-based problems in introductory mechanics physics courses
,”
Eur. J. Phys.
35
(
5
),
055019
(
2014
).
9.
P.
Klein
,
J.
Kuhn
,
A.
Müller
, and
S.
Gröber
, “Video Analysis Exercises in Regular Introductory Physics Courses: Effects of Conventional Methods and Possibilities of Mobile Devices,” in
Multidisciplinary Research on Teaching and Learning
, edited by
Wolfgang
Schnotz
,
Alexander
Kauertz
,
Heidrun
Ludwig
,
Andreas
Müller
, and
Johanna
Pretsch
(
Palgrave Macmillan
UK, London
,
2015
), pp.
270
288
.
10.
P.
Klein
,
S.
Gröber
,
J.
Kuhn
, and
A.
Müller
, “
Video analysis of projectile motion using tablet computers as experimental tools
,”
Phys. Educ.
49
(
1
),
37
40
(
2014
).
11.
V.
Pereira
,
P.
Martín-Ramos
,
P. P.
da Silva
, and
M. R.
Silva
, “
Studying 3D collisions with smartphones
,”
Phys. Teach.
55
,
312
313
(
May
2017
).
12.
D.
Brown
and
A. J.
Cox
, “
Innovative uses of video analysis
,”
Phys. Teach.
47
(
3
),
145
150
(
March
2009
).
13.
L.
Moggio
,
P.
Onorato
,
L. M.
Gratton
, and
S.
Oss
, “
Time-lapse and slow-motion tracking of temperature changes: Response time of a thermometer
,”
Phys. Educ.
52
(
2
),
023005
(
2017
).
14.
M. P.
Strzys
,
S.
Kapp
,
M.
Thees
,
J.
Kuhn
,
P.
Lukowicz
,
P.
Knierim
, and
A.
Schmidt
, “
Augmenting the thermal flux experiment: A mixed reality approach with the HoloLens
,”
Phys. Teach.
55
,
376
377
(
Sept.
2017
).
15.
Neximo Labs, Framelapse–Time Lapse Camera (Google Play, 2017)
, https://play.google.com/store/apps/details?id =com.Nishant.Singh.DroidTimelapse (temporary web address).
16.
tsaedek, VidAnalysis free v. 1.63 (Google Play, 2017)
,.https://play.google.com/store/apps/details?id=com.vidanalysis.free (temporary web address).
17.
T. L.
Bergman
and
A.
Lavine
,
Fundamentals of Heat and Mass Transfer
, 8th ed. (
Wiley, Inc
.,
Hoboken, NJ
,
2017
).
18.
This is a simplified model for the actual pathways for the transfer of energy. In reality, three major pathways come into play: the free convection from the warm water to the glass flask, the conduction through the flask walls, and the forced convection from the flask to the room air. For advanced classes, all 3 phenomena can be taken in consideration and their relative effect pondered by changing the fan speed.
19.
C. R.
Mattos
and
A.
Gaspar
, “
Introducing specific heat through cooling curves
,”
Phys. Teach.
40
,
415
416
(
Oct.
2002
).
20.
G.
Planinšič
and
M.
Vollmer
, “
The surface-to-volume ratio in thermal physics: From cheese cube physics to animal metabolism
,”
Eur. J. Phys.
29
(
2
),
369
384
(
2008
).
21.
J. B.
Will
,
N. P.
Kruyt
, and
C. H.
Venner
, “
An experimental study of forced convective heat transfer from smooth, solid spheres
,”
Int. J. Heat Mass Transfer
109
,
1059
1067
(
2017
).
22.
C.
Leinbach
, “
Beyond Newton’s law of cooling – Estimation of time since death
,”
Int. J. Math. Educ. Sci. Technol.
42
(
6
),
765
774
(
2011
).
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