Oscillations and resonance
What units are used to measure the period of an oscillation?
Second
What is the loudest animal on earth?
A whale
A whale can emit sound up to 188 dB
What is a wave?
Propagation of an oscillation through space or a medium
Why is there no sound in vacuum?
Because there are no particles in vacuum and sound is a propagation of particle oscillations
In what medium do sound waves travel the fastest?
In solids
State two differences between free and forced oscillations
Free oscillation occurs due to internal forces of the systems, while forced oscillation occurs due to external forces. The amplitude of the free oscillation is decreasing, while the amplitude of the forced oscillation is constant.
What genre of movies use infrasound in movie soundtracks?
Horror movies. Infrasound causes anxiety and fear in people.
Free points!
There are no free points in physics
What is infrasound?
Sound which has frequency of less than 16 Hz (20 Hz)
What determines the speed of sound propagation in different materials?
The density if the material
What does the period of a mathematical pendulum depend on?
It's length
What is the fear of sound called?
Acousticophobia
What are the two types of waves?
Transverse and longitudinal
What does the pitch of a sound depend on?
On its frequency. The higher the frequency, the higher the pitch.
What is the name of the phenomenon, when the waves combine to strengthen or weaken each other?
Interference
What is the main condition of resonance?
the INTERNAL FREQUENCY of the system MATCHES THE FREQUENCY OF THE EXTERNAL FORCE
What is the approximate height of the highest recorded water wave (megatsunami)? (+-25m)
524 m
On July 9, 1958, in Alaska
What is the main property of waves?
transfers energy without transferring matter
Which of the physical quantities describing waves does not change when the wave passes from one medium to another? (eg air to water)
Frequency
What phenomenon allows us to hear a person talking around the corner of a building even though we cannot see them?
Diffraction
Give two examples of the occurrence of resonance.
The bridge collapses as the army marches across the bridge foot by foot
The glass is broken by the singer's voice
In a quiet classroom, when there is no class, about 30 dB of background noise was measured. How loud is the quietest room in the world? (+- 5 dB)
-24.9 dB
visitors say they can hear the blood running through their veins in this room
What type of wave cannot form in a gas?
Transverse
Explain the difference between sound intensity and loudness.
Sound intensity is an objective measurable characteristic (energy transmitted by sound) and loudness is a subjective perception of sound heard by a person
How does the pitch of an audible tone change if the distance between the listener and the sound source increases?
The sound heard is of a lower pitch than that emitted by the source.