COM S5

Question 1

Explain why sound is a useful and versatile form of communication

Answer 1

• ¬Sound  form of energy that requires a medium of transmission (e.g. air or water)
• Useful and versatile form of communication  can be produced as well as detected
• Can be used as signal day and night
• Can be used over distances when animals cannot see, smell or touch each other
• Does not require contact between organisms in order to send and receive messages
• Can convey complex messages  has many features that can be varied e.g. pitch, loudness, speed and length of each sound

Question 2

Explain that sound is produced by vibrating objects and that the frequency of the sound is the same as the frequency of the vibration of the source of the sound

Answer 2

• Sound = produced by vibrating objects
• Vibrations transferred along adjoining molecules
• Cannot travel through a vacuum (empty space)
• Sound waves must have medium to travel through  act by compressing particles in medium
 Medium = solid, liquid or gas

Question 3

Explain that sound is produced by vibrating objects and that the frequency of the sound is the same as the frequency of the vibration of the source of the sound (frequency)

Answer 3

• Frequency: number of waves that pass a given point per second (measured in Hz)
• Frequency determines Pitch: how high or low the sound is
• (Pitch and Frequency is not the same thing!)
• The frequency of the sound is the same as the frequency of the vibration of the source of the sound

Question 4

Explain that sound is produced by vibrating objects and that the frequency of the sound is the same as the frequency of the vibration of the source of the sound (amplitude)

Answer 4

•	Amplitude: 
 Depends on amount of energy in wave 
 Loudness 
•	The greater the energy of the compression  the greater the amplitude of the wave 
 The louder the sound

Question 5

Plan and perform a first-hand investigation to gather data to identify the relationship between wavelength, frequency and pitch of a sound
name an aim.

Answer 5

To determine the relationship between wavelength, frequency and pitch of a sound

Question 6

Plan and perform a first-hand investigation to gather data to identify the relationship between wavelength, frequency and pitch of a sound
name a method

Answer 6

1. Use a tuning fork, piece of rubber and piece of wood/stand
2. Hit the tuning fork on rubber and immediately place on wood stand
   • Determine that higher frequency of notes produces a high pitch sound
   • Higher the frequency  the shorter the wavelength

Question 7

Plan and perform a first-hand investigation to gather data to identify the relationship between wavelength, frequency and pitch of a sound
whats the conclusion?

Answer 7

• Velocity = frequency x wavelength
• High pitched sound = high frequency & short wavelength
• Loud = large amplitude
• Soft = small amplitude
• Loudness of sound determined by energy carried by the wave

Question 8

Outline the structure of the human larynx and its assistance in sound production

Answer 8

• Larynx = voice box
• Front of neck
• Front part = ‘Adam’s apple’
• Contains vocal cords  flexible folds of muscle and ligament
 Enable humans to make sounds with the tongue, lips, nose and mouth

Question 9

Production of sound with other associated structures?

Answer 9

• Production of sound  air from lungs causes vocal cords in larynx to open and close rapidly  produces tiny vibrations of weak sound
 Sound amplified through throat, palate, mouth and nasal cavity
 Palate: directs airflow from larynx to mouth or nose
 Nasal cavity: produces unique voice
 Tongue, lips and jaw: produce different speech sounds – ‘uh’ ‘ph’ ‘g’

Question 10

Bats and their structure used to produce sounds?

Answer 10

Ultrasonic signals from larynx
– Used to search for insects and other prey & to avoid obstacles in darkness
– Ultrasonic waves = high frequency sound waves

Question 11

Fish and their structure used to produce sounds?

Answer 11

Rubbing their fins or gills or by vibrating the swim bladder

Question 12

Male grasshoppers and crickets and their structure used to produce sounds?

Answer 12

1. Rubbing veins on the base of forewings together

2. Creating friction between inner surfaces of hind thighs

Question 13

Male frogs and their structure used to produce sounds?

Answer 13

Squeeze lungs while shutting nostrils and mouth  air flows over vocal sac