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VIBRATION  AND WAVE
Vibration is defined as the oscillating motion of the body regularly through the equilibrium point.
One Vibration :  A – B – A – C - A
Amplitude Of Vibration  :   A – B   ,  A – C
Period and Frequency of Vibration 
n  Period  (T)
n  Time for every vibration
n  Time of all vibration divided number of  vibration
n  T = t/n
n  The unit in SI is second (s)
n  T = 1/f
n  Frequency (f)
n  Number of vibration every 1 second
n  Number of vibration divided time of all vibration
n  f = n/t
n  The unit in SI is hertz (Hz)
n  f = 1/T
n  Amplitude of vibration is not influency number of period and frequency of vibration
n  the meaning of wave is the vibration  propagates to bring energy
n  TRANSVERSAL WAVE
n  Direction of vibration is perpendicular to direction of propagation
n  The wave on seawater surface
n  The ripple of water
n  The light wave
n  The radio wave, TV, HP
n  The wave on the rope vibrates perpendicular to direction of propagation

n  LONGITUDINAL WAVE
n  Direction of vibration is coincident to direction of propagation
n  The wave in the seawater
n  The sound wave
n  The wave  of slinky
n  vibrates  by  coincident to direction of propagation
ABCD  = compression             
           
   
TRANSVERSAL WAVE
n  Hill of wave         = ABC
n  Valley of wave = CDE
n  Peak of wave     = B, F
n  Bottom of wave               = D
n  Amplitude           = B B1
n  One wave           = A B C D E
n  Wavelength(λ) = A E
n  (λ) =  Lamda

n  Wavelength is the distance travelled by wave in one period or the length of one wave
n  Wave Period is  time needed to pass one wave
n  Wave frequency is the number of wave formed in 1 second.
n  Speed of wave is the distance passed by wave within 1 second.
Speed of wave  (v) is the distance passed by wave within 1 second.
 V= λ.f           v  =  λ /T
where
λ = Wavelengthits unit is meter (m).
T = Periodits unit is sekon (s).
 f = frequency, its unit is Hertz (Hz)
Property of Wave :
n  Wave can reflected ( reflection ).
                 Wave can reflected ,if  a wave hits obstacle wall.
                Example: the light wave, the water wave, the sound wave, etc.
n  Wave can refracted ( refraction )
                 Wave can refracted, in this case the light wave, if through two optic medium is different its dencity by the angle.
                 Example : the light wave from air to water by the gradient angle.
n  Wave can defracted ( Defraction).
                Example :
                The sound wave,
     Its prove, we can hear the sound  from a room through very thin hole.
                The light wave, its prove is the image of thin narrow hole dropped on the floor appear in wide.
n   Wave can interferenced (interferency).
Exercise:
1.The number of peaks and valleys at the wave  picture above are....

2. Look at the picture In question number 1. Its amplitude and the period are respectively....

3. The period of wave, if its wavelength is 5 m and its speed is 10 m/s, is ....
4. Look at the picture!
    If the distance A to D 15 meter and be travelled in 7,5 second, then its speed is . . .

5. Look at the followng figure of a pendulum. A motion of 1 vibrations is shown as the following successive motion ......
                                                      

 
6. The number of vibrations performed in every second is . . . .

7. If the frequency of a vibration is 4 Hz, the period of such a vibration is . . . .

8. The following is considered as a transverse wave, except . . . .

9. The number of waves are performed in each second is called. . . .

10. If the vibration direction is perpendicular to the direction of wave propagation, it means that the wave is a/an . . . .
11. Look at the picture!
 
                                  12 m
The wavelength of the wave is . . . .

12. A pendulum performs swings with the number of vibrations 20 times in 10 seconds. The frequency  is . . . .

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Example :
1.    The vulcanic material of mass 10 tons is thrown   vertical upward. The height of it that can be reached is 15,000 meters. The work of vulcano is ….( g = 10 N/kg)
Solution :
W= m.g.h
    =10000 kg.10 N/kg.15000 m
    = 1,500,000,000 J
2. A box contains substance of metal totalize1,000 Newton in boosting up to use inclined plane similar at the picture. Force of power minimum which is needing in order to can make move going up is ….
                                                            
3 m
                                                      4 m
Solution :
   s2 = 32+42 ; s = 5m
   F= w .h /s = 1000N . 3m / 5m = 600 N
2.    A lever with burden arm 50 cm, lever length 2 m, burden weight 600 Newton, hence the minimum power force (F) used the burden to earn upraised is….    
Solution :
F= w.lw / lf = 600 N. 50cm  / 150 cm = 200 N
3.    Consider the picture burden as heavy as 230 Newton, lifted by using free pulley, weight the pulley 10 Newton, hence the power force (F) that is needed minimize upraised in order to….

Solution :
F =  ½.W =  ½. (230+10)N = 120 N.
 4.  The bread of width 12 cm will be cut with a knife.
       The force applied is 24 N and the sharp edge has a thickness of 0.4 mm. The pressure exerted on  the bread is ….

Solution :
       A = 12 cm x 0.4 mm
           = 120 mm x 0.4 mm
           = 48 mm2
           = 48 /10000 m2
       P  = F / A = 24 N / 48 m2 = 5000 N
                               10000

5. Given F1 = 12000N, A1=60 A2. The magnitude of force required to lift the car is ….
Solution :
F2 = (F1.A2) / A1 = 12000N . A2 / 60 A2 = 200 N
6.


How much  minimally force will be needed to pull the object of mass 15.5 kg, out of the water, if the volume of the object 0.0005 m3? (the weight of pulley is ignored, ρ water = 1000 kg/m3, g = 10N/kg).

Solution :
FA = ρ.g.V = 1000 kg .10 N/kg . 0.0005 m3  = 5  N
F =1/2( m.g  -  FA )=1/2 (15.5 kg . 10N/kg)  -  5 N)  =1/2( 155 N – 5 N) =1/2x 150 N=75N
7. A body is pushed with force of  36 N, so that it moves in acceleration.  If the mass of a body is  6 kg and  there is no friction which works on the body, then the acceleration of the body is….

Solution :
a = F/m = 36 N/ 6kg = 6 ms-2
                                            
8. Mass of the body is 30 kg on the Earth. Given earth gravitational acceleration is 10 m/s2. If on the moon acceleration due to gravity is 1/6 of acceleration due to gravity on the earth, then the body’s weight on the moon is ....

Solution :
Wm = 1/6 . m.g = 1/6 x 30 kg x 10 ms2 = 50 N





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Science-Physics Directorat 2011 Question Solution
4. s = v.t = 8x5 = 40 m

5. a = Vt-Vo = 20-10 = 10 ms-2
             t           1
6. a = Vt-Vo =  5 - 0 = 5 ms-2
             t           1

7. a = Vt-Vo = 12-10 = 1 ms-2
             t         6 – 4
9. W = F . d = 100N x 15m = 1500 J
10.  PE = m.g.h = 1,5 kg x 10 ms-2 x 10m = 150 J

11. m= 20 tons = 20000 kg
       V = 72 km/h x (5/18) = 20 m/s
      KE = ½ m v2 = ½ . 20000kg. 202 = 10000 x 400 = 4000000 J = 4000 kJ

12. ME = PE + KE = (200 + 400) J = 600 J
13. MA = Lf = 12.5 cm = 1.7 times
                 Lw     7.5 cm

14. F= w xh  =  m.g x h  = 20kg.10 ms-2.10m = 80 N
               S                s                       2.5 m

17. a = Vt-Vo =  3 - 9 = -3 ms-2
             t              2
      F= m .a = 5 kg . (-3 ms-2 ) = -15 N  (tanda – berarti melawan arah gerak benda)

22. A= 0.1 cm2 = 0.00001 m2      
      P=  F = 25N            =  250000 N m-2
             A    0.00001 m2      
 
23. P=  F = 10N            =  20 N m-2 , etc
             A    0.5 m2      

24. PH = ρ.g.h = 1000kg/m3 .10ms-2.(22-12)m  =  1000 Nm-2
                                                                     100
26. FA  = ρ.g.V = 1000 kgm-3. 10ms-2.(15/1000000)m3 = 0.15 N

27. F2 = F1 x A2 =  100 N x 200 cm3 = 400 N
                  A2                               50cm3
28. P2 = P1.V1/V2 = 5 Pa x100cm3/25cm3 = 20 Pa.
29. X = (76- 1600/100)cmHg = (76-16)cmHg =60 cmHg
30. h = ( 76-71) x 100 m = 500  m



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