3.3 Principle of superposition of waves and formation of stationary waves

• When waves overlap, their displacements add together.
• Destructive interference occurs when waves cancel each other out, resulting in a decrease in amplitude.
• Constructive interference results in an increase in amplitude.
• Destructive interference results in a decrease in amplitude.
• What are examples of phase differences for constructive interference?

  0, ±2π, ±4π
• Constructive interference occurs when waves reinforce each other.


  True
• Destructive interference results in an increase in amplitude.

  False
• Constructive interference occurs when waves are in phase.

  True
• Destructive interference occurs when waves are out of phase.
• The phase differences for destructive interference are odd multiples of π.
• Destructive interference occurs when crests align with troughs.
• What are the conditions for the formation of stationary waves?

  Same frequency, opposite direction
• What is an example of stationary waves in real-world applications?

  Musical instruments
• The phase difference between the two waves in stationary waves must be an odd multiple of π.


  True
• What is the condition for constructive interference?

  Waves are in phase
• When does constructive interference occur?

  Waves are in phase
• For destructive interference, the phase difference must be an odd multiple of π.


  True
• What type of interference occurs at antinodes in stationary waves?

  Constructive
• The relationship between wave speed, frequency, and wavelength is given by the equation v = fλ.
• Wavelength is the distance between two consecutive points in phase
• A stationary wave with a frequency of 10 Hz and a speed of 30 m/s has a wavelength of 3 m.


  True
• The amplitude of a stationary wave is uniform across the wave.

  False
• Order the steps for constructive and destructive interference based on phase difference:

  1️⃣ In phase (0, ±2π, ±4π, etc.)

  2️⃣ Constructive interference

  3️⃣ Out of phase (π, ±3π, ±5π, etc.)

  4️⃣ Destructive interference
• Destructive interference occurs when waves are out of phase
• Antinodes in stationary waves are points of maximum amplitude.


  True
• Nodes in a stationary wave are fixed points of minimum amplitude.

  True
• What is the amplitude like at the nodes of a stationary wave?

  Fixed
• What is the definition of the wavelength of a stationary wave?

  Distance between points in phase
• The speed of a wave is directly proportional to its frequency and wavelength.


  True
• Stationary waves are formed by the interference of waves traveling in opposite directions.
• What is the principle of superposition of waves?

  Displacements of waves add
• What happens to the amplitude of waves during constructive interference?

  It increases
• Define constructive interference in terms of wave displacement.

  Waves add, increasing amplitude
• Define destructive interference in terms of wave displacement.

  Waves cancel, decreasing amplitude
• What is the condition for constructive interference in terms of phase?

  Waves are in phase
• Destructive interference occurs when waves are in phase.

  False
• Constructive interference happens when crests align with crests and troughs align with troughs.


  True
• What is the effect on wave amplitude during destructive interference?

  Decrease in amplitude
• In stationary waves, points of maximum amplitude are called antinodes.
• What are stationary waves formed by?

  Interference of two waves