1

• What is a stationary wave?

  A wave that stores, but does not transfer energy
• How do stationary waves form on a piece of string?

  Two waves interfere while traveling in opposite directions
• What is a node?

  A point of zero displacement in a standing wave
• How do nodes occur in a standing wave?

  Where two waves destructively interfere and cancel
• What is an antinode?

  A point of maximum displacement in a standing wave
• How do antinodes occur in a standing wave?

  Where two waves constructively interfere to form a maximum
• Describe the arrangement of nodes and antinodes at the fundamental frequency.

  • One central antinode
  • One node at each end
• What apparatus generates a wave in a piece of string?

  A vibration generator driven by a signal generator
• What apparatus alters the length of oscillating string?

  A bridge can be moved along the string
• Why should the signal generator be operated for several minutes before use?

  To allow the frequency to stabilize
• What must be added to the clamp stand for safety?

  A counterweight or g-clamp
• How does the length of the string affect the frequency of the first harmonic?

  Longer string length decreases frequency
• How does the string’s mass per unit length affect the frequency of the first harmonic?

  Increased mass per unit length decreases frequency
• How does tension in the string affect the frequency of the first harmonic?

  Increased tension increases frequency
• What equation calculates the frequency of a string’s first harmonic?

  Equation not provided in the material
• How can the tension in a string be varied?

  By attaching a mass hanger to the end
• What safety precautions should be taken when using mass hangers?

  Never stand directly under a mass hanger
• What is the tension produced in the string with 3 masses of 100 grams each and a 100-gram hanger?

  3.924 N
• How can you measure the mass per unit length of a piece of string?

  Divide mass by the string’s length
• What is the advantage of using a long piece of string when measuring mass per unit length?

  Lower percentage uncertainty in measurement
• What happens when the frequency is changed to double that of the first harmonic?

  String resonates in its second harmonic
• What equation determines the speed of a wave from its wavelength and frequency?

  $v =$$f\lambda$
• What is the wavelength relative to the length of the oscillating string in its fundamental mode?

  $\lambda =$$2L$
• How can wave speed be calculated from the string’s tension and mass per unit length?

  Equation not provided in the material
• How can wave speed be determined from a graph of 1/f against L?

  Wave speed is given by 2/gradient