A guitar string is plucked and creates a sound that is a pure sine wave. After a short time $t$, which of the following statements about the sound waves it is emitting is true

  1. The amplitude of oscillation has decreased, while the frequency stays basically the same.
  2. The number of oscillations per second has decreased significantly as well as the amplitude.
  3. The wavelength of the sound waves increases.
  4. The wave-speed and the amplitude both decrease.

For a standing wave on a string that is oscillating with the lowest possible frequency for a standing wave, how many nodes will be present?

  1. 0
  2. 1
  3. 2
  4. 3

Where is the amplitude of oscillation greatest for a standing wave on a string.

  1. At the nodes
  2. At the anti-nodes
  3. Halfway in between the nodes and anti-nodes
  4. Amplitude is constant throughout the length of the string.

These two waves are approaching each other with constant but opposite velocities. The snapshot graph shows their positions and velocities at t=0. What will the sum look like at t = 2 s?

  1. A
  2. B
  3. C
  4. D

For a standing wave on a string that is oscillating in the 1st (Fundamental) Harmonic Frequency, how many wavelengths will be visible in the string?

  1. 0
  2. 1/2
  3. 3/2
  4. 1

For a standing wave on a string that is oscillating in the 3rd Harmonic Frequency, how many wavelengths will be visible in the string?

  1. 0
  2. 1/2
  3. 1
  4. 3/2

(the following 3 questions all relate to this setup and image) A string is fixed in place at points A and E as shown in the diagram. It is made to oscillate in a standing wave at a frequency $f$. The image shows a snapshot in time of the string as it oscillates. The coordinate directions of $x$ and $y$ are also shown in the diagram.


Which harmonic is this string oscillating in?

  1. 1st (Fundamental)
  2. 2nd Harmonic
  3. 3rd Harmonic
  4. None of the above

Assuming the moment in time shown (this is a snapshot style image of the string) is when the amplitude of oscillation is the greatest, what can you say about the velocity of the string at point B?

  1. The velocity is equal to 0.
  2. The velocity is in the $+x$ direction
  3. The velocity is in the $+y$ direction
  4. The velocity is in the $-x$ direction

Assuming the moment in time shown (this is a snapshot style image of the string) is when the amplitude of oscillation is the greatest, what can you say about the acceleration of the string at point B?

  1. The acceleration is equal to 0.
  2. The acceleration is in the $+x$ direction
  3. The acceleration is in the $+y$ direction
  4. The acceleration is in the $-y$ direction

A standing wave on a string is observed to have a wavelength of 20 cm. The string itself is 40 cm long. How many anti-nodes are present in this oscillating system.

  1. 1
  2. 2
  3. 3
  4. 4

A 100 cm string oscillates with a fundamental frequency of 80 Hz. You pinch the string exactly at 25 cm away from one end, thus creating a node at that location. The string continues to vibrate in a higher harmonic standing wave, but the frequency is changed. What is the new wavelength?

  1. 25 cm
  2. 50 cm
  3. 100 cm
  4. 200 cm

Superposition refers best to which aspect of wave motion?

  1. That the wave speed is constant.
  2. That two waves can be added together make a new wave.
  3. That some positions along a standing wave have a lot more motion than others.
  4. That standing wave harmonics don't depend on the tension in the rope, just the force of gravity.