A
Longitudinal waves
True or False - Sound waves travel faster in gases than liquids
False
Can sound waves travel in vacuum (empty space)?
No, they cannot
Give an example of a sound with high pitch.
(Listen to sound)
True
A medium is a material described by Chemical Composition and ...
Phase (solid, liquid, or gas), density, and Temperature
Which wave parameter identifies the loudness of a sound?
Amplitude
Which parameter identifies the pitch of the sound?
Frequency
What is Frequency?
The number of cycles (vibrations) travelling in 1 second
What is the meaning of rarefaction?
The decrease in pressure
What is the meaning of compression?
Increase in pressure
What is the name of the instrument that displayes a sound wave as a transverse wave?
Oscilloscope
What is wavelength?
The distance between a point on one wave to the same point on the next wave.
Draw a sound wave displayed at the oscilloscope having high pitch and loudness.
Draw on the whiteboard
Draw sound waves affected by the Temperature inversion. Explain what happens
During night, sound waves are refracted by means of this phenomenon. As a consequence, s receiver can receive the sound clearly than during day time.
Can an echo occur "before" 0.1 seconds after the emission of the sound from the sourse?
No, because the sound waves overlap cancelling out or shrinking their effect.
A boat sends ultrasound waves at a frequency of 27 kHz. If the wavelength of these ultrasound waves is 5.4 cm, find the depth of the sea bed considering the echo is received after 3 seconds.
depth = 2187 m (approx)
What is the minimum time required to hear an echo distinctly?
0.1 seconds
An ultrasound wave has a frequency of 36 kHz and its speed=2700 m/s. How much is its wavelength?
0.075 m
True or False - When a (sound) wave moves from a point A to a point B, also the particles of the wave move from A to B.
False - When a wave travels from point A to point B, the energy moves, but the particles do not travel with the wave.
Why do sound waves in a gas spread slower than liquids and solids?
Before particles interact less one another, being without bonds and free to move randomly (they are not constrained by bonds)
Why do violins produce high-pitch sounds while basses produce low-pitch sound?
A violin produces a higher pitch than a bass because the bass has longer strings, which vibrate with a longer wavelength and lower frequency.
Explain an example in which a sound wave is "diffracted"
Example: When listening a person speaking behing the corner
When a wave is Refracted, which parameters change and which other remain the same?
During Refraction, Frequency is constant while wavelength and speed change