science

• What is the unit for frequency?

  Hertz (HZ)
• How is frequency defined in terms of waves?

  It is the number of waves per second.
• What is the human hearing range in Hertz?

  20 to 20,000 Hz
• Which animal has the largest hearing range?

  The elephant
• In which medium do sound waves travel fastest?

  In solids
• What happens to sound waves when they meet another medium?

  They are absorbed.
• Why do walls block sound?

  Some sound is reflected and absorbed.
• What occurs when sound waves reflect?

  Echoes occur.
• How do cinemas and theatres reduce echoes?

  By using soft materials to absorb sound.
• What are the key terms related to sound waves?

  • Amplitude
  • Frequency
  • Hertz
  • Wavelength
• How is frequency measured?

  In hertz
• What does the pitch of a note depend on?

  On the wavelength
• What is the distance between the top of two waves called?

  Wavelength
• What is the amplitude of a wave?

  Half the total height of the wave.
• What is the term for the number of vibrations each second?

  Frequency
• What is ultrasound used for in medicine?

  To scan organs and pregnancy
• How is ultrasound used for cleaning?

  By directing ultrasonic waves through liquid.
• Why is ultrasound used to check for cracks in metals?

  It reflects off cracks to detect faults.
• How do fishing boats use echo-location?

  By sending ultrasonic clicks and detecting echoes.
• Why are ultrasound scans safer than X-rays during pregnancy?

  Because X-rays can damage cells.
• What is the purpose of the special gel used in ultrasound scans?

  To ensure ultrasound waves penetrate the abdomen.
• Why is it useful to have a moving picture in ultrasound scans?

  To observe the baby's heart pumping.
• What do we call sound waves we can't hear?

  Ultrasound
• What parts of the body show up on an X-ray?

  Bones
• What parts of a baby's body show up on an ultrasound scan?

  Soft tissue and bones
• What is the role of the outer ear?

  To guide sound waves into the ear canal.
• What is the function of the ear drum?

  To vibrate in response to sound waves.
• What do the ossicles (ear bones) do?

  They transmit vibrations to the cochlea.
• What is the role of the cochlea?

  To convert vibrations into nerve signals.
• What is the unit for frequency?

  Hertz
• What is the human hearing range?

  20 to 20000 Hz
• Which animal has the largest hearing range?

  Elephant
• How do sound waves travel in different mediums?

  Faster in solids, then liquids, then gases
• Why do walls block sound?

  Some sound is reflected and some is absorbed, but not much goes through
• What is the measure of frequency in Hertz?

  Frequency
• What does the pitch of a note depend on?

  Wavelength
• What is the distance between the top of two waves called?

  Wavelength
• What is half the total height of a wave called?

  Amplitude
• What are the uses of ultrasound?

  Medicine, cleaning, and crack detection
• How do fishing boats use ultrasound?

  They use echo-location to detect schools of fish under the boat