Waves, sound, EM, eye

Front

Transverse waves

How is energy transferred?

Example?

Back

waves where the particles move up and down, perpendicular to the direction the wave travels

Energy is transferred through oscillations

Water and EM waves

Front

Longitudinal waves

How is energy transferred?

Example?

Back

waves where the particles move back and forth, parallel to the direction the wave travels

Energy is transferred through vibrations

Sound waves

Front

Wavelength. Measured in?

Amplitude. Measured in?

Frequency. Measured in?

Crest

Trough

Back

Wavelength (λ): the distance between two consecutive crests or two consecutive troughs

 

• It represents one complete cycle of the wave

• Measured in metres (m)

 

Amplitude (A) : the height of the wave from its resting position to the crest or trough

 

• A larger amplitude carries more energy

• Measured in metres (m)

 

Frequency (f): the number of complete waves passing a fixed point each second

 

• Measured in Hertz (Hz) where 1Hz = 1 wave per second

• Higher frequencies correspond to shorter wavelengths, as more waves fit into a given time period

 

Crest: highest point of a wave

Trough: lowest point of a wave

Front

Back

Front

Formula for wave frequency, speed and wavelength

Back

v = f x λ

Front

Sound

What do the vibrations create?

Back

a type of longitudinal wave, requiring a medium to travel through as it is created by vibrations

• These vibrations cause particles to move back and forth, creating regions of compression (where particles are pushed close together) and rarefaction (where particles are spread further apart)

Front

How does amplitude and frequency affect sound?

How does sound travel in different mediums?

Back

Bigger amplitudes create louder sounds, while smaller amplitudes make quieter sounds.

 

Higher frequencies result in higher-pitched sounds, while lower frequences produce deeper sounds.

Sound travels slowest in gases, faster in liquids, and fastest in solids - because particles are closer together making it easier to transfer vibrations

Front

Doppler Effect

Sound?

Light?

Back

explains how waves change when the source of the waves is moving

Sound - when an object making sound moves towards you, the sound waves get squished together, making the wavelengths shorter = higher frequency = higher pitch. If the source is moving away the waves stretch = lower frequency = lower pitch.

 

Light - if a light source moves towards you, its light waves compress and their wavelengths get shorter, making the light shift to the blue end of the spectrum (blueshift). If the source moves away the waves stretch and light shifts towards the red end of the spectrum (redshift).

Front

Explain how the ear responds to sound waves

Back

1. Pinna: the outer part of the ear - it collects sound waves and funnels them into the ear canal

2. Ear Canal: directs the sound waves towards the tympanic membrane (eardrum)

3. Tympanic Membrane (Eardrum): vibrates at the same frequency as the incoming sound waves converting sound energy into kinetic energy

4. Ossicles: three small bones in the middle of the ear (malleus, incus, and stapes) - amplify the vibrations from the eardrum and pass them to the oval window

5. Oval window: a membrane at the entrance to the inner ear - it transfers the vibrations into the fluid-filled cochlea

6. Cochlea: a spiral-shaped structure in the inner ear filled with fluid. Inside, the Organ of Corti contains sensory receptors called hair cells - when vibrations enter the cochlea, the fluid inside the cochlea is set into motion creating waves, which push against the basilar membrane causing it to move and bend the hair cells against the tectorial membrane. The bending of the hair cells generates electrical signals which are transmitted via the auditory nerve to the brain

 

Different hair cells in the cochlea are tuned to detect sounds of varying pitches.

 

• High pitched sounds (short wavelengths) stimulate hair cells near the oval window

• Low pitched sounds (long wavelengths) stimulate hair cells near the apex of the cochlea

Front

Electromagnetic spectrum

Back

the full range of electromagnetic waves, from radio waves with the longest wavelengths to gamma rays with the shortest. Each different type of wave differs in wavelength, frequency and energy.