circular motion final
TRANSCRIPT
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PHISICK TASK CHAPTER 3
3.1 UNIFORM CIRCULAR
MOTION
3.2 CIRCULAR MOTIONTRANSVERING
3.3 CIRCULAR MOTION
WITH ACCELERATION
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3.1 uniform circular
motion Uniform circular Motion is a particle that
moves circularly with radius R and constantspeed.
Gerak Melingkar Beraturan adalah sebuahbenda yang bergerak melingkar denganjari-jari R dan kelajuan tetap
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R
B
B
A
A
B
Notes
A : Particle A ( benda A)
B : Particle B ( Benda B)
A : Linier Velocity A(kecepatan linier A)
B : Linier velocity B (Kecepatan linier B
: Angulairvelocity(kecepatan
sudut)Sketch of circular motion
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Period and Frequency (Periode dan Frekuensi)Period (Periode)
Is the time elapses to reach 1 circular motion on a
thing.Adalah waktu yang diperlukan untuk menempuh 1putaran pada sebuah benda.
Formula :T: Period (Periode)..secondt : Time (Waktu)...secondn: The number of circular
motion (jumlah putaran)n
tT
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Frequency (Frekuensi)
Is a number of circular motion on athing in 1 second.Adalah jumlah putaran pada sebuahbenda dalam waktu 1 sekon.
Formula:
t
nf
f : frequency(frekuensi)..Hz
n : The number of circular motion(jumlah putaran)
t : time(waktu)..second
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The Relation between Period andFrequency
(Hubungan antara Periode dan Frekuensi)
And
So,
And
n
tT
t
nf
f
1T
T
1
f
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Linier / Tangensial velocity (KecepatanLinier / Tangensial )
Linier/Tangensial Velocity (Kecepatan Linier/ tangensial)Is the distant which covered per unit oftime.Adalah jarak yang ditempuh per satuanwaktu.
To reach the distant of 1 circular motion
(2R) needs 1 period (T).Untuk menempuh jarak 1 putaran (2R)
memerlukan 1 periode (T).
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So :
linier velocity = distant / period
or
With radius R
= 2Rf (m/s)
T
R2v
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ngu a r e oc y ecepa ansudut)
Angulair Velocity is angle which coveredper unit of time.Kecepatan sudut adalah sudut yang
ditempuh per satuan waktu To reach 360O or 2 radian on 1 circular
motion needs 1 period (T)
Untuk menempuh 3600
atau 2 radiandalam satu putaran memerlukan 1periode(T)
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So:
Angulair velocity =2 / T
Or
(read : Omega)1 circular / rotation = 2 radian
)s/rad(T
2
)s/rad(f2
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The Relation between Linier Velocity (V)
and Angulair Velocity ().
(Hubungan antara Kelajuan Linier (V)
dan Kecepatan Sudut ().
V : Linier Velocity(Kecepatan Linier)
: Angulair velocity
(kecepatan sudut)
R : Radius (jari-jari)
= . R
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Centripetal Acceleration(Percepatan sentripetal)
is The change of velocity per limit oftime
Adalah perubahan kecepatan per satuanwaktu.Formula :
oras= 2R (m/s2)
Rva
2
s
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Fs=m2
.R
Fs
R
A
R
mvFs
2
Fs = Centripetalforce
(N,Dyne)m = mass (kg,gr)
V = linier speed(m/s,cm/s)
R = raius
= Angulairvelocity(rad/s)
Centripetal Force ( Gaya Sentripetal)
A Body connected with rope than moves uniform circularly.Sebuah benda dihubungkan dengan tali kemudian bergerakmelingkar beraturan.
Formula :
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3.2 Circular motiontransvering
(hubungan perputaran)
DIRECT (Langsung)
R1
R2
v1
v2
1 =
2
2
2
1
1
R
v
R
v
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INDIRECT ( Tidak langsung )
V1 = v2
1.R1 = 2.R2
R1
R2
R1R2
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If the pulleys connected with a gear, so :
Jika roda terhubung dengan sebuahgir,maka :
or
nA&nB : amount of gear A and gear B
(jumlah gir A & gir B)f: Frequency(frekuensi)T: Period (Periode)
nA .fA = nB .fB
TB
nB
TA
nA
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And
mA & mB :amount of cyclus(jumlahputaran)
RA & RB : radius A and B( jari-jari A danB)
mA . RA = mB. RB
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3.3 Circular motion withacceleration
(gerak melingkar berubah
beraturan) The Formula is similar with Linier
Motion.
Rumusnya sama dengan gerak lurus. They are: : Angulair acceleration
/decelleration
t: final angulair velocity( kecepatan sudut akhir)o: initial angulair velocity
(kecepatan sudut awal)
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Vt : Final linier velocity(kecepatan linier akhir)
Vo : Initial linier velocity
(kecepatan linier awal) :amount of rotation(jumlah
putaran) read:teta
t= o + .t
t2=o2+2
t = o - t
2
0t
2
1t
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at : tangensial acceleration(percepatan tangensial)
as : centripetal acceleration
(percepatan sentripetal)
atot: total acceleration
(percepatan total)
at = . R
as = 2 . R
22
tot asata
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EXERCISE 1
UNIFORM CIRCUALR MOTION1. A particle moves circularly with constant
velocity 300 cm/s and radius is 2,5 cmfind: a) Period and frequency
b) Angulair velocity ( in rpm)c) Centripetal acceleration
2. A particle moves circularly in 10 second covered5 circular. If radius is 4mfind : a) Period and frequency
b) Angulair velocity ( in rpm)c) Centripetal acceleration
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3. A dinamo has diameter 20 cm. Moves
circularly in 150 rpmfind: a) Period and frequencyb) Linier velocity
4. A particle moves circularly with radius = 4min 2 second. Happens angle displeacement(perpindahan sudut) 1 / 6 circularfind : a) Angle displeacement in radian
b) Period and frequencyc) Angulair velocityd) Linier velocity
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5. A thing has mass 50 gram connected with rope thathas long 1 meter. Moves circular and in 10 secondhappens 50 circular.
Find : a) Linier velocity
b) Centripetal acceleration
c) Tension rope (centripetal force)
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1. Four pulleys (wheel) with radius R1=5 cm, R2=15 cm,R3= 10 cm,R4= 25 cm as in the diagram bellow. Thefirst wheel moves with a frequency of 2 / Hz.Find : a) Angulair velocity of wheel 1b) Tangensial velocity of forth wheel
EXERCISE 2CIRCULAR MOTION TRASVERING
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2. A door trap bicycle with a front gear radius 12 cmand back gear radius 4 cm. The wheel radius is 18 cmeach. The front gear moves with a period of 3second .find : a) The time needed to reach the
distance 18 km
b) if the amount of the front gear 40,
find the amount of the back gear
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3. The machine use 2 wheel like diagram bellow. Smallerwheel has radius 5 cm and moves circularly on 120
rad/sfind : a) Linier velocity both wheel
b) If bigger wheel has radius 16cm, find the angulair velocity in rpm
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4. Wheel A has radius 4cm and wheel B has radius 10cm. Wheel B connected with wheel C (radius = 3 Cm).
If wheel A moves circularly by the same directionwith watch and angulair velocity 15 rad/s.
find : linier velocity of wheel D has radius 16 cm.
AB
C
D
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5. An electric motorcycle rotate wheel A which has
radius 10 cm. Wheel A connected with rope on otherwheel that has radius 50. If the motorcycle givesangulair 200 rad/s to wheel A
find : Angulair velocity wheel B and centripetal
acceleration of wheel B.
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EXERCISE 3CIRCULAR MOTION WITH
ACCELERATION1. A wheel rotates in 2 second the angulair changefrom 30 rpm to 20 rpm. The radius is 10 cmfind: a) Angulair deceleration
b) The amount of rotation2. At first a wheel do nothing reach angulair
velocity 64 rad/s on 16 second.find: a) Angulair acceleration
b) Angle which covered
c) If the radius of wheel 10 cm. Find thecentripetal acceleration
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3. A disk with radius 15 cm at first rotate 25 rad/s and
its brake till become 15 rad/s. During it, the disk hasrotate 40 radian.
find : a) Angulair decceleration
b) How long time needed to stop since the first
brakec) Before brake find tangensial velocity,centripetal acceleration and total
acceleration