THE INFLUENCE
OF RADIUS ON ANGULAR VELOCITY IN UNIFORM CIRCULAR MOTION
Adytia Permana
Putra 1,*) , Ai Awaliyah 2,*) , Dian Rahmatuloh 3,*)
, Adam Malik 4,*)
*) Prodi Pendidikan Fisika UIN Sunan Gunung Djati Bandung, Bandung,
Indonesia.
1
adytia.app@gmail.com
2
aiawaliyah@gmail.com
3 rahmatulohdian@gmail.com
4 adammalik@uinsgd.ac.id
Abstract. Object
experience circular motion will have angular velocity. One of factors influence
of angular velocity is radius. this study purpose to know influence radius on
angular velocity in circular motion. This study using experiment method who
assisted with simple practices tool of uniform circular motion. Data obtained
from circular motion experiment using radius who different. The radius is 20 cm
and 30 cm. the result from experiment showing that long radius will obtain angular velocity who
smaller from short radius.
Key Word : Experiment Method, Angular Velocity, Circular Motion.
1.
Introduction
Every object which rotating will experience circular motion who
produce angular velocity. Circular motion / rotation motion is motion a object
which produce orbit like circular who surroundings point of center (Westfall, 1972) . Yasin Unsal said that motion an object
which have radius r and moving in orbit of circular namely 'circular motion' (Unsal, 2011) angular velocity
defined as change of angular position of object who moving circular every time
unit (Tipler, 1998) . Relationship between linear velocity
and angular velocity is
Information :
Linear Velocity (m/s)
Change of Position (m)
Change of Time (s)
Angular Velocity (rad/s)
Chang of Angle (rad)
Radius (m)
Because a circle have radius, hence angular velocity will
influenced by radius. hence :
Our purpose making this study is to know influence radius on angular
velocity of a object who moving of uniform circular. Nuri maked study about
"moving toward centre" who said that centripetal acceleration, linear
velocity, and angular velocity is three of mathematic quantity who draw
principal attention to analysing uniform motion a objects who be in circle (Balta, 2015) .
The study was conducted by Dewanto and Sudarsono in studying about "system
modeling of force and traction of wheel", saying that rise traction of
wheel larger but rise mentioned not linear (Dewanto & Sudarsono, 2003) . Yulkipli and his
friends also was conducted study to calculate angular velocity used fluxgate
sensor, who calculated based rev quantities which happen from a wheel of gear (Yulkifli, Anwar, & Djamsi, 2010)
In this the
study, data obtained from practicum tool of circular motion which created by
researcher with price which enough cheap, hence the practicum tool can maked by
anyone. therefore, this study purposed to know the radius which kind will
result larger angular velocity ? long radius ? or short radius ? with used
practicum tool was created.
2.
Experiment Methode
Researcher take
data as direct to field used experiment method which assisted with practicum
tool of circular motion. experiment method is a certain manner for searching
relationship between two factors which deliberate appeared by researcher with
eliminating or lessing or ignore a factors which disturb.
Data obtained
from experiment of uniform circular motion for searching relationship between radius
and angular velocity. Independent variable in this study is radius, while the
dependent variable is period. hence with period, we can calculate value of
angular velocity, with equation :
Experiment executed
with use radius different. The radius is 20 cm. and 30 cm with each experiment
repeated three times of experiment. Period value measuremented using digital
stopwach with carefulness 0.1s
.
3.
Result and Discussion
a. Experiment I : Use Radius 20
cm.
On this experiment, researcher obtain result in table form.
Tabel 1 experiment Uniform Circular Motion
use radius with long 20 cm
No
|
Jari –Jari (m)
|
Periode (s)
|
Kecepatan Sudut (Rad/s)
|
1
|
0.2
|
0.6
|
433.3
|
2
|
0.2
|
0.4
|
650.0
|
3
|
0.2
|
0.8
|
325.0
|
Rata
– Rata
|
0.6
|
469.4
|
|
Based on table I, using radius with long 20 cm obtain average
period 0.6 s. until average angular velocity obtained is 469.4 rad/s. Different
period value because practicum tool not yet perfect and use stopwacht not accurate.
Hence result from each experiment become average for obtain ideal value.
b.
Experiment II Use Radius 30 cm
Second experiment obtain result in table form :
Tabel 2 experiment Uniform Circular Motion
use radius with long 30 cm
No
|
Jari
–Jari (m)
|
Periode
(s)
|
Kecepatan
Sudut (Rad/s)
|
1
|
0.3
|
1.8
|
200.0
|
2
|
0.3
|
1.2
|
300.0
|
3
|
0.3
|
1.4
|
257.1
|
Rata
– Rata
|
1.5
|
252.4
|
|
Tabel 2 show different with table 1. On the tabel 2, average period
larger is 1.5 s, while the angular velocity smaller is 252.4 rad/s. Different
period value because practicum tool not yet perfect and use stopwacht not
accurate. hence result from each experiment become average for obtain ideal
value
c.
Comparison of period value on
experiment I and II
Graph 1. Comparison of period value on experiment of uniform circular motion use radius 20 cm and 30 cm
Information :
Blue = Experiment I
Red = Experiment II
Graph 1 show that period value on experiment
1 smaller compared experiment 2 . That because different long of radius on each
experiment. Long of radius on experiment
1 is 20 cm obtain average period 0.6 s. Long of rradius on experiment 2 is 30
cm obtain average period 1.5 s. We can see that if longer radius, hence period
value will larger. Because in circular motion, period will equal straight with
radius
d.
Comparison of angular velocity value
on experiment I and II.
Graph 2
Comparison of angular velocity value on experiment of uniform circular
motion use radius 20 cm and 30 cm
Information :
Blue = Experiment I
Red = Experiment II
On the graph 2, angular velocity on experiment I larger compared
experiment II. This because angular velocity influence the period and the
period influence the radius. Value of average angular velocity on experiment I
is 469.4 rad/s. Result obtained equal with pronouncement Jose in his study
about measurement of angular velocity on rotation motion, said that subjects do
not estimate a unique global angular velocity, but that they perceive a
non-rigid disk, with angular velocity falling inversely proportionally with
radius (Barraza & Grzywacz, 2002) . Hence that longer radius,
angular velocity smaller because in the uniform circular motion, angular
velocity equal retrun with radius
4.
Conclusion
Based Data obtained and result was discucc, hence can said that
angular velocity influenced by the radius. Because orbit of circular motion is
circle . hence will have a radius. Longer radius, period obtained will larger,
and larger periode, angular velocity will smaller. So larges radius,angular
velocity will smaller.
References
Balta, N. (2015). Moving Toward
Centre. Physics Education, V, 50.
Barraza, J. F., & Grzywacz, N.
M. (2002). Measurement of Angular Velocity in the Perception of Rotation. Vision
Research, 42, 2457–2462.
Dewanto, J., & Sudarsono, B.
(2003). Pemodelan Sistem Gaya Dan Traksi Roda. Jurnal Teknik Mesin, V,
64-69.
Halliday, & Resnick. (1991). Fisika
Jilid I (Terjemahan). Jakarta: Erlangga.
Tipler, P. A. (1998). Fisika
untuk Sains dan Teknik - Jilid I (Terjemahan). Jakarta: Erlangga.
Unsal, Y. (2011). A Simple Piece of
Apparatus to Aid The Understanding of Relationship between Angular Velocity
and Linear Velocity. Physics Education, XLVI, 265-269.
Westfall, R. S. (1972). Circular
Motion in Seventeenth-Century Mechanics. 63, 184-189.
Yulkifli, Anwar, Z., & Djamsi,
M. (2010). Desain Alat Hitung Kecepatan Sudut Berbasis Sensor Magnetik
Fluxgate. Jurnal Saintek, II, 56-65.
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