circular motion final

8/3/2019 Circular Motion Final

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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

circular motion final

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