1. Properties of Waves Ms. T.

2. 4 Basic Properties of Waves O Amplitude O Wavelength O Frequency O Speed

3. Amplitude O Maximum distance the particles of the medium carrying the wave move away from the resting place

4. Amplitude of Transverse Wave O The maximum distance the medium moves up or down from the resting place. O Measure from resting place to top of crest or to bottom of trough

5. Amplitude of Transverse Wave O The amplitude of the wave is related to the energy of the wave. O The greater the energy the greater the amplitude. Amplitude = 3 cm Amplitude = 1 cm

6. Amplitude of a Longitudinal Wave O A measure of how compressed or rarefied the medium becomes O Greater amplitude= tighter compression

7. Property 2: Wavelength O A wave travels a certain distance before it repeats. O The distance from crest to crest or from trough to trough is one wavelength. WAVELENGTH 2 cm 1 cm

8. Frequency O The number of waves that pass a certain point in a certain amount of time. O Frequency is measured in HERTZ (Hz) per second O A wave that passes a point every second has a frequency of 1Hz. If 2 waves pass a point every second, it has a frequency of 2Hz. O Go To this animation click below: O http://www.pbslearningmedia.org/asset/lsps 07_int_frequency/ http://www.pbslearningmedia.org/asset/lsps 07_int_frequency/

9. Speed O Different waves travel at different speeds. O Speed = the distance a wave travels in a certain amount of time O Formula: Speed = Wavelength x Frequency O Example: If a wave has a wavelength of 2 meters and a frequency of 3 Hz, What is the speed? O S = W x F O S = 2m x 3Hz O S = 6m/s

10. Formulas for Frequency & Wavelength O If you know 2 of the values in the speed formula, you can find the third quantity: O Frequency = Speed Wavelength O Wavelength = Speed Frequency

11. Find Speed Using Formula: O S = W x F O A wave has a wavelength of 3mm and a frequency of 4Hz. What is the speed? O S = W x F O S = 3mm x 4 Hz O S = 12mm/s O A wave has a wavelength of 5cm and a frequency of 2Hz. What is the speed? O S = W x F O S = 5cm x 2 Hz O S = 10cm/s

12. Finding Frequency using Formula O F = S or F = S ÷ W W O A wave has a speed of 6cm/s and a wavelength of 2cm. What is the frequency of the wave? O F = S/W O F =6/2 (divide) O F= 3 Hz O A wave as a speed of 10mm/s and a wavelength of 5cm. What is the frequency of the wave? O F = S/W O F =10/5 (divide) O F= 2 Hz

13. Finding Wavelength using Formula O Wavelength = Speed or W = S÷F Frequency O A Wave has a speed of 12m/s and a Frequency of 2Hz. What is its wavelength? O W= S/F O W = 12/2 O W = 6m O A wave has a speed of 24cm/s and a frequency of 6 Hz. What is its wavelength? O W= S/F O W = 24/6 O W = 4m

14. Summary: What I should know and be able to do. O What are the 4 properties of waves? O Which wave property is directly related to energy? O Which wave properties are distances? O Which wave properties are relative to time? O What is the formula for speed? Frequency? Wavelength? O 2 Waves have the same wavelength and frequency. How do their speeds compare? O Calculate: A wave’s frequency is 2Hz and its wavelength is 4m. What is the wave’s speed?