1. 1
   A referee at a football match blows a whistle that produces a sound with a frequency of 3000 Hz. A player standing 170 m away hears the whistle a short time after it is blown, since sound travels through air at approximately 340 m/s.

   (a)

   What type of wave is the sound produced by the whistle?

   [1 mark]

   • ALongitudinal, with compressions and rarefactions of air particles along the direction of travel
   • BTransverse, with air particles oscillating perpendicular to the direction of travel
   • CLongitudinal, because it can travel through a vacuum
   • DTransverse, because it can be reflected but not refracted

   (b)

   Calculate the time it takes for the sound of the whistle to reach the player standing 170 m away.

   [1 mark]

   • A0.5 s
   • B2 s
   • C57 800 s
   • D5 s

   (c)

   State the frequency range of human hearing, and explain whether the referee's whistle, at a frequency of 3000 Hz, would be audible to a typical person.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A music teacher uses a microphone connected to an oscilloscope to compare the sound produced by a tuning fork with the sound produced by a violin string tuned to the same note. Both sounds are displayed as traces on the oscilloscope screen.

   (a)

   On the oscilloscope screen, the trace produced by the tuning fork's sound shows a wave with a larger amplitude than the trace of the violin string's sound at the same frequency. What does this indicate about the tuning fork's sound compared with the violin string's sound?

   [1 mark]

   • AThe tuning fork's sound has a longer wavelength than the violin string's sound
   • BThe tuning fork's sound has a higher pitch than the violin string's sound
   • CThe tuning fork's sound travels faster than the violin string's sound
   • DThe tuning fork's sound is louder than the violin string's sound

   (b)

   The teacher then plucks a different violin string that produces a note with a visibly higher frequency trace on the oscilloscope. What does the student hear as a result of this higher frequency?

   [1 mark]

   • AA quieter sound
   • BA louder sound
   • CA higher-pitched sound
   • DNo audible difference, since frequency does not affect what is heard

   (c)

   Describe how the teacher could use the oscilloscope and microphone to measure the frequency of the sound produced by a vibrating tuning fork.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A group of students carries out a practical investigation in the school hall to measure the speed of sound in air, using two microphones, a measured distance, and a timing device.

   (a)

   Describe how the students could investigate the speed of sound in air using two microphones connected to a timer, positioned a known distance apart, with a sound source such as a hand clap made near the first microphone.

   [3 marks]

   (b)

   The students obtain a set of repeated time measurements for the same distance, but notice that the calculated speed of sound varies slightly between repeats. Suggest two reasons for this variation, and describe one improvement the students could make to their method to obtain a more reliable value.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   An orchestra conductor notices that the sound reaching the back rows of a large, historic concert hall sounds noticeably quieter and less clear than the sound reaching the front rows, even though the same instruments are playing at the same amplitude throughout the performance.

   (a)

   Explain, using the properties of longitudinal sound waves, why sound might become quieter with distance from its source, and describe how the frequency and amplitude of the sound relate to what an audience member perceives as pitch and loudness.

   [6 marks]

   (b)

   The conductor is told that the hall's designers, working before electronic amplification was available, shaped the ceiling and walls to help reflect sound towards the back rows. Explain how the reflection of sound waves from the hall's surfaces could help listeners at the back hear a louder and clearer sound, and evaluate why simply making the orchestra play louder would not fully solve the problem of sound quality at the back of the hall.

   [6 marks]

   Total for question 4: 12 marks

End of questions