1. Properties of waves

2. Waves
A Wave is the motion of disturbance. In a wave, particles vibrate with simple harmonic motion.
Medium: a physical environment through which a disturbance can travel (Ex: water or air)
Mechanical Waves: a wave that requires a medium through which to travel
Sound waves can not travel through outer space.
Electromagnetic Waves: do not need a medium to travel
Ex: visible light, radio waves, ultraviolet, microwaves, Xrays

3. Relationship between shm and wave motion
Sine Wave: a wave whose source vibrates with SHM.
Name given from the graph of the trigonometric function: y=sin x
If we focus on one point of the rope, we can see that it vibrates around its equilibrium position with SHM.

4. Measures of simple harmonic motion
Amplitude – the maximum displacement from equilibrium.
Units: meters
Period – the time that it takes a complete cycle to occur.
Symbol: T Units: seconds
Frequency – number of cycles or vibrations per second
Symbol: f Units: hertz (Hz), 𝟏 𝒔 , s-1
Wavelength – distance between 2 crests or 2 troughs
Symbol: λ (lambda) Units: m, nm

5. Transverse Waves
Transverse Wave: a wave whose particle vibrate perpendicularly to the direction the wave is traveling.

6. Longitudinal Wave
Longitudinal Wave: a wave whose particles vibrate parallel to the direction the wave is traveling.

7. 𝑻= 𝟏 𝒇 𝒗=𝒇𝝀 Wave Equations T= Period [s] v= speed [m/s]
𝑻= 𝟏 𝒇 𝒗=𝒇𝝀
T= Period [s] v= speed [m/s]
f= frequency [ 𝑠 −1 ] f= frequency [ 𝑠 −1 ]
λ=wavelength [m]

8. 𝐸𝑛𝑒𝑟𝑔𝑦= 𝐴𝑚𝑝𝑙𝑖𝑡𝑢𝑑𝑒 2 (mechanical waves)
Wave travel
Waves transfer energy through vibration. The greater the amplitude, the more energy a wave carries in a given time interval.
𝐸𝑛𝑒𝑟𝑔𝑦= 𝐴𝑚𝑝𝑙𝑖𝑡𝑢𝑑𝑒 2 (mechanical waves)

9. Practice
A spring-block oscillator oscillates with a period of 2.5 seconds. What is its frequency?

10. Practice
A piano string tuned to middle C vibrates with a frequency of 262 Hz. Assuming the speed of sound in air is 343 m/s, find the wavelength of the sound waves produced by the string.