C12 Waves

What do waves transfer?

energy not matter

how do particles in a a wave move

-They oscillate to and from a point

Transverse waves

-Direction of vibrations of the particles is perpendicular to the direction in which the wave travels

Longitudinal wave

direction of travel of the wave is parallel to the direction in which the wave travels

Mechanical waves

-Travels through a medium, can be transverse or longitudinal

Electromagnetic waves

-Can travel through a vaccum, and are transverse waves

Amplitude of a wave

-Height of the wave crest or depth from the trough, from the midpoint of the wave

Wavelength

-Distance from one crest to the next or trough to trough

Frequency

-Number of wave crests passing a point in 1 second

Period

-Time it takes for one wavelength to pass a point

Incident waves

Waves travelling towards a barrier or a boundary

What happens in terms of waves if a barrier is placed in a tank

-Reflection takes place at the barrier,the reflected wavefront moves away from the barrier, at the same angle to the barrier as the incident wavefront

When do waves change speed and wavelength- refraction

when they cross a boundary between different substances

When waves meet a boundary with a different substance they may be:

-Totally or partially reflected -Transmitted through the substance -Absorbed by the substance

What are sound waves caused by?

-Mechanical vibrations

What can sound waved not travel through?

-A vaccume ( air space)

How is a echo produced

-When sound waves are reflected off flat surfaces

What does the pitch of a note depend on

the frequency of the sound wave

-Higher frequency of wave =

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How do we hear sound waves

-Sound waves travel through air, then reach the eardrum, making it vibrate, sending electrical signals to the brain

What does the ability to hear high frequencies decline with

age

Human ear can hear?

20hz to 20khz

Wave on a string practicle 5

-Adjust frequency of oscillater until theres a single loop on the string-Note the frequency of oscillator -Measure length of loop and calculate wavelength for a single loop-Calculate speed of wave on the string -change frequency on oscilator to obtain more loops