1. An Introduction to Waves
3U Physics

2. What is a wave?
A wave is a disturbance which carries energy from one location to another.

3. What is a wave?
A wave is a disturbance which carries energy from one location to another.
The material the disturbance travels through is the ?
The movement of the disturbance is referred to as ?

4. What is a wave?
A wave is a disturbance which carries energy from one location to another.
The material the disturbance travels through is the medium.
The movement of the disturbance is referred to as ?

5. What is a wave?
A wave is a disturbance which carries energy from one location to another.
The material the disturbance travels through is the medium.
The movement of the disturbance is referred to as propagation.

6. 2 Types of Waves
A longitudinal wave is a wave in which the particles of the medium move in a direction parallel to the direction of propagation.

7. 2 Types of Waves
A longitudinal wave is a wave in which the particles of the medium move in a direction parallel to the direction of propagation.

8. 2 Types of Waves
A longitudinal wave is also called a pressure wave or a sound wave.

9. 2 Types of Waves
A longitudinal wave is also called a pressure wave or a sound wave.
The regions of increased pressure/density are called ?.
The regions of decreased pressure/density are called ?.

10. 2 Types of Waves
A longitudinal wave is also called a pressure wave or a sound wave.
The regions of increased pressure/density are called compressions.
The regions of decreased pressure/density are called ?.

11. 2 Types of Waves
A longitudinal wave is also called a pressure wave or a sound wave.
The regions of increased pressure/density are called compressions.
The regions of decreased pressure/density are called rarefactions.

12. 2 Types of Waves
A transverse wave is a wave in which the particles of the medium move in a direction perpendicular to the direction of propagation.
Although sound waves are not transverse waves, we often represent them as transverse waves because transverse waves are easier to draw.

13. 2 Types of Waves
The vertical axis represents not displacement but pressure.

14. Snapshot of a Transverse Wave
The dashed line represents the equilibrium position of the particles.

15. Snapshot of a Transverse Wave
The positions of maximum displacement are referred to as crests (positive displacement) and troughs (negative).
The maximum displacement is the amplitude.

16. Snapshot of a Transverse Wave
The positions of maximum displacement are referred to as crests (positive displacement) and troughs (negative).
The maximum displacement is the amplitude.
Amplitude = Energy

17. Snapshot of a Transverse Wave
The distance between one crest and the next crest (or one trough and the next trough) is the

18. Snapshot of a Transverse Wave
The distance between one crest and the next crest (or one trough and the next trough) is the wavelength, represented by

19. Snapshot of a Transverse Wave
The distance between one crest and the next crest (or one trough and the next trough) is the wavelength, represented by l.

20. Snapshot of a Transverse Wave
The time it takes one complete wavelength to pass a single point is the

21. Snapshot of a Transverse Wave
The time it takes one complete wavelength to pass a single point is the period, represented by

22. Snapshot of a Transverse Wave
The time it takes one complete wavelength to pass a single point is the period, represented by T.

23. Snapshot of a Transverse Wave
The time it takes one complete wavelength to pass a single point is the period, represented by T.

24. Snapshot of a Transverse Wave
The number of complete wavelengths that pass a single point in one second is the frequency, represented by f.

25. Frequency Frequency is measured in units of 1/s or s-1 or Hertz (Hz).
“I do not think that the wireless waves I have discovered will have any practical application.”

26. Wave Speed
The speed of a wave is therefore:

27. Wave Speed
The speed of a wave is therefore:

28. Wave Speed
The speed of a wave is therefore:

29. Wave Speed The speed of a wave is therefore:
The speed of a sound wave in air at room temperature (20oC) is 344 m/s.

30. Sound Wave Example
Calculate the wavelength of the sound wave produced by a 125 Hz tuning fork in air at 20oC.

31. Sound Wave Example
Calculate the wavelength of the sound wave produced by a 125 Hz tuning fork in air at 20oC.

32. Sound Wave Example
Calculate the wavelength of the sound wave produced by a 125 Hz tuning fork in air at 20oC.

33. More Practice Inquiry Activity: Slinky Waves
Homework: An Introduction to Waves