1. Oscillatory Motion

2. Types of Motion
Transitional motion
Periodic motion

3. Periodic Motion
It is the motion which is regularly repeated in equal period of time

4. Types of Periodic Motion
Wave motion
Oscillatory motion

5. The Concept of Oscillatory Motion

6. The Concept of Oscillatory Motion
Observation:
The oscillating body moves on both sides around its original position (A).
This motion is repeated in equal period of time.
The displacement of the oscillating body around its original position are equal.
The velocity of the oscillating body reaches its maximum value when it passes its original position and decreases gradually when it goes far from it

7. Oscillatory motion
It is the motion of the oscillating body around its rest point, where the motion is repeated in equal period of time.

8. Question
The following figure represent an oscillatory motion for a simple pendulum.
The maximum velocity of the pendulum is at point(s)………..(A/B/C/C, B).
The velocity decreases at point(s)………..(A/B/C/B, C)

9. Graphical Representation of The Oscillatory Motion:

10. Concept of OscillatoryMotion
amplitude
Complete oscillation
Periodic time
frequency

11. Amplitude The maximum displacement on the right side at point (B).
The maximum displacement on the left side at point (C).

12. Amplitude
It is the maximum displacement done by the oscillating body away from its original position.
The measuring unit of the amplitude is meter “m” or centimeter “cm”.

13. What is meant by? The amplitude of an oscillating body is 2 cm.
This means that maximum displacement of the oscillating body away from its original position is 2 cm.

14. Complete Oscillation
A → B → A → C → A.
It is the motion of an oscillating body when it passes by a fixed point on its path two successive times in the same direction.

15. Complete Oscillation
The complete oscillatory movement include 4 displacements (four amplitudes).
AB – BA – AC – CA.

16. Exercise In which graph, the amplitude is larger?
The amplitude of curve (1) is larger than the amplitude of curve (2).
How many complete oscilations do exist between the points x and y represented on both graphs?
In curve (1): 3
In curve (2): 4

17. Periodic Time
It is the time taken by an oscillating body to make one complete oscillation.
The measuring unit of periodic time is second “sec”

18. Periodic Time (T) The periodic time = time in seconds
number of complete oscillations
The periodic time of an oscillating body which makes 240 oscillations in one minute equals…………….. 1
4 sec

19. What is meant by?
The periodic time of an oscillating body is 0.2 seconds.
this means that the time taken by this oscillating body to make one complete oscillation is 0.2 second.

20. Frequency (F)
It is the number of complete oscillation made by an oscillating body in one second.
The measuring unit of frequency is Hertz “Hz”

21. Frequency (F)
Kilohertz= 103 HZ
Megahertz= 106 HZ
Gigahertz= 109HZ

22. Frequency (F) The frequency= number of complete oscillations
time in seconds
A simple pendulum makes 540 complete oscillations in a minute, so its frequency is………..
9 Hz.

23. The Relation Between Frequency and Periodic Time
Frequency (F) x Periodic time (T)= 1
Frequency (F)= 1 T
Periodic time(T)= 1 F

24. Proplem
Calculate the periodic time and frequency for an oscillating body that makes 300 complete oscillations in half a minute.
t= 0.5 x 60 =30 sec.
T= t(sec)
no.of complete oscillation
T= 30 = 0.1 sec
300
F= 1 = 1 = 10 Hz
T 0.1

25. REAL LIFE APPLICATION
MICROWAVE OVEN

26. Quiz

27. A-COMPLETE:
1-………...motion and……..motion are 2 types of periodic motion.
2-The complete oscillation includes…….successive displacements, each of them is called……….
B-G.R:
The oscillatory motion is considered as periodic motion.
C- problem:
If the frequency of an oscillating body is 10 HZ, find:
1- its periodic time
2- the time taken to make 300 complete oscillations.
3- the number of complete oscillations this body makes in a minute.