waves

1. Lesson two
Wave motion

2. 1-Wave
Is the disturbance that propagates and
transfers energy in the direction of
propagation.
2- Wave motion
Is the motion produced as results of the
vibration of the medium particles at a
certain moment and in a definite
direction.

3. 3- Line of wave propagation
It is the direction through which the
wave propagates.
4-Transverse wave
Is a disturbance in which the particles of
the medium vibrate perpendicular to the
direction of wave propagation.

4. 5- The crest
Is the highest point of the particles of
the medium in transverse wave.
6-The trough
Is the lowest point of the particles of the
medium in transverse wave.

5. 7-Longitudinal wave
Is the disturbance in which the particles
of medium vibrate along the direction of
wave propagation.
8-The compression
Is the area at which the particles of the
medium are of highest density and
pressure.

6. 9-The rarefaction
Is the area at which the particles of the
medium are of lowest density and
pressure.

7. Waves
Mechanical
Wave
Electromagnetic
Wave

8. There are two types of waves
Types of waves
Transverse
Wave
Crest Trough
Longitudinal
Wave
Compression Rarefaction

9. Concepts of wave
motion
Wave length
Amplitude
Wave Velocity
Wave frequency

10. *Concepts of wave motion:-
1- Wave length (λ):
Wavelength of transverse wave: Is the
distance between two successive crests
or troughs.
Wavelength of longitudinal wave: Is the
distance between the centers of two
successive compressions or rarefactions.

11. *Concepts of wave motion:-
The unit for measuring wavelength (λ) is
“meter” or “cm”.
2- Amplitude
The maximum displacement done by
particles of medium away from their rest
positions.

12. 3-Wave velocity = Distance covered by the wave “m”
Time “sec”
-The velocity of sound waves through
air =340 m/s.
- The velocity of sound waves through
water = 1500 m/s.
-The velocity of sound waves through
wood = 1850 m/s.

13. 4- Wave frequency: It is the number of
waves produced from the source in one
second.
Wave frequency= number of produced waves/ time “sec”
Periodic time of the wave (T) = 1/ Frequency
(F) Wave velocity (V) “m/sec”= Frequency (F)”Hz”
x Wavelength (λ)”m”

14. *Life applications:
- Physiotherapy tubes (Jacuzzi):
It is a tube where water moves in the
form of circular waves.

15. *Uses of Jacuzzi:
1- Treatment of sprains and
cramps by using hot water.
2-Treatment of nervous tension by
using cold water.

16. The role of waves in transferring energy:
-Procedure:
1- Arrange the dominoes’ pieces in a row
at equal distance from each other.
2-Push the first piece.

17. -Observation:
The pieces fall one after the other, as
well as they don’t change their position.
-Conclusion:
The disturbance that propagate and
transfer energy in the direction of
propagation is a wave.