4.8 Standing Waves (2/10) Flashcards
(20 cards)
Up until this point, we have been studying travelling waves. Travelling waves transfer________________from one ____________to another.
For the physics of music chapter, we will start studying standing waves.
a) energy
b) location
True or false: standing waves store energy inside the wave rather than transferring it.
True.
Travelling waves transfer energy. Standing waves store energy.
Why is it called a standing wave?
It appears to be staying in the same place.
How are standing waves formed?
When a wave travels down a medium, reflects off a barrier, and returns up the medium again.
Throw-back to a previous chapter: what is wave interference?
When two or more waves meet and interact with each other.
Reminder: interference can be constructive or destructive
What causes a standing wave?
Standing waves are caused by the interaction of the initial wave with the reflected wave. When the frequency is just right, the wave interference creates an organized pattern.
looks like the wave is TRAPPED between the two barriers.
Under what conditions do standing waves occur?
Specific frequencies produce neat standing waves. These produce **tones. **
Other frequencies result in messy patterns (white noise).
Fill in the blank: Standing waves can only happen at ____. At other times, white noise is produced.
specific frequencies
True or False: Standing waves transfer energy from one place to another.
False
Standing waves store energy instead of transferring it.
What sound is produced by a wave pattern reflecting off a barrier at frequencies that DO NOT produce standing waves?
White noise. The wave pattern looks messy and disorganized.
Only certain frequencies create standing wave patterns.
Standing waves can occur both on a string or in a tube. The string can be fixed or loose. A tube can be open or closed.
Which musical instruments are examples of:
a) a string fixed at both ends
b) a tube open at only one end
c) a tube open at both ends
a) guitar
b) flute
c) clarinet
True or false: Standing waves can occur both on a string AND in a tube
True
Musical instruments are a good example
What types of boundaries can strings that produce standing waves have?
fixed or loose
What types of ends can tubes that create standing sound waves have?
a) open-open
b) open-closed
What is an example of a string instrument with fixed boundaries?
Guitars have the strings fixed at both ends
What type of tube is a flute?
Flutes are an open-open tube
What type of tube is a clarinet?
Clarinets are a closed-open tube
Do strings and tubes produce standing waves in the same way?
Yes! Both produce standing waves in the same way
What do we call the spots in standing wave where the amplitude is zero?
Nodes
What do we call the spots in standing wave where the amplitude is greatest?
Antinodes
