10. WAVES - BASIC WAVE PROPERTIES

10. WAVES - BASIC WAVE PROPERTIES
Key notes:
1. Waves are means of energy transfer.
2. Frequency is the number of waves generated per second. Unit - hertz (Hz)
which is also in cycles/second.
3. Wavelength is the distance
a) Between consecutive troughs.
b) Between consecutive crests.
c) Between two consecutive similar points on a wave. Unit - metre (m).
4. Wave velocity is the distance travelled by a crest in one second. Unit - m/s.
5. Amplitude is the maximum displacement of a particle from its equilibrium
position. Unit - metre (m).
6. Periodic time T is the time for one complete wave to pass through a certain
point.
7. In a transverse wave, the vibrations of the particles are perpendicular to the
direction of wave travel.
8. Examples of transverse waves are light waves and water waves.
9. In a longitudinal wave, the vibrations of the particles are parallel to the
direction of wave travel.
10. An example of longitudinal waves is sound waves.
11. The particles in a medium vibrate at the same frequency as the waves passing
through it.
12. Examples of transverse waves are light waves and water waves.
13. In a longitudinal wave, the vibrations of the particles are parallel to the
direction of wave travel.
14. An example of longitudinal waves is sound waves.
15. The particles in a medium vibrate at the same frequency as the waves passing
through it.
16. Waves are reflected such that the angle of incidence is equal to the angle of
reflection.
17. Refraction of waves is the change in the direction of travel due to a change in
speed.
18. Water waves move faster in deep water. Their speed and wavelength decrease
O LEVEL PHYSICS REVISION NOTES
in shallow water.
19. Water waves are refracted to become more parallel to the deep-shallow
boundary when moving from a deeper region into a shallower region.
20. Electromagnetic waves are a family of transverse waves that travel at the
speed of light, 3 x 10^8 m/s.
21. They can pass through a vacuum.
22. The only visible component of electromagnetic waves is visible light.
23. Gamma-rays have the shortest wavelengths while radio waves have the
longest wavelengths.
Formulas:
 Periodic Time (T)
T = 1 / f seconds / cycle
T - periodic time
f - frequency
 Velocity (v)
velocity = frequency x wavelength
v = fλ