Resonance matching of forced vibration and natural frequency

Resonance matching of forced vibration and natural frequency of an object, resulting in large amplitude of waves (standing wave + constructive interference from source)

Sound breaking wine glass video Tacoma Narrows collapse video

Speed of Sound waves travel through air at a speed of 343 m/s Sound waves travel faster in denser materials, because sound waves are the longitudinal vibrations of molecules, so more molecules means faster transfer

Practice v=λf This tuning fork that we used for the resonance demo has a printed frequency of X Hz. Let’s calculate the wavelength of the sound waves it produces. Now let’s compare that to the length of open space.

Resonance and Pipes The wavelengths and frequencies of a sound can be determined by ◦ The length of a “pipe” ◦ If the pipe is “open” or “closed”

Open Pipes Resonance occurs when antinodes are at the same distance as the pipe Like waves with a loose end

(One Side) Closed Pipes Resonance occurs when antinodes are at the open end and nodes are at the closed end Like waves with a fixed end

A tuning fork oscillates with a frequency of 256 hertz after being struck by a rubber hammer. Which phrase best describes the sound waves produced by this oscillating tuning fork? a)mechanical waves that require a medium for transmission b)electromagnetic waves that require no medium for transmission c)mechanical waves that require no medium for transmission d)electromagnetic waves that require a medium for transmission

In a demonstration, a vibrating tuning fork causes a nearby second tuning fork to begin to vibrate with the same frequency. Which wave phenomenon is illustrated by this demonstration? a) interference b) Nodes c) Resonance d) the Doppler Effect

At an outdoor physics demonstration, a delay of 0. 50 second was observed between the time sound waves left a loudspeaker and the time these sound waves reached a student through the air. If the air is at STP, how far was the student from the speaker? a)1. 5 x 108 m b)1. 5 x 10 -3 m c)1. 7 x 102 m d)6. 6 x 102 m

Homework Handout