Ultrasound

• How do some animals like bats use ultrasound?

  For communication or echolocation
• What is the frequency range of ultrasound?

  Above 20,000 Hertz
• How do humans produce ultrasound?

  Using electrical devices
• What happens when ultrasound hits a boundary between two mediums?

  Some waves are reflected, some transmitted
• What is the process called when only some ultrasound waves are reflected?

  Partial reflection
• How can we determine the distance to a boundary using ultrasound?

  By knowing speed and reflection time
• Why is ultrasound considered safe?

  It does not involve radiation
• What is a common use of ultrasound in medicine?

  Scanning fetuses
• How does an ultrasound device work during a prenatal scan?

  It transmits and receives sound waves
• What happens to ultrasound waves when they pass from one medium to another?

  Some waves are reflected back
• What indicates a fault in an object during ultrasound testing?

  Unexpected reflected waves
• How can ultrasound be used in industrial quality checks?

  To detect cracks in solid objects
• What is echo sounding also known as?

  Sonar
• How do boats use ultrasound for navigation?

  To sense submarines and objects underwater
• If an ultrasound pulse travels at $1400 \text{ m/s}$ and takes $6 \text{ seconds}$ to return, what is the distance to the seafloor?


  $4200 \text{ meters}$
• What is the formula to calculate distance using ultrasound?

  Distance = Speed × Time
• Why is it important to consider the time taken for ultrasound waves to return?

  It affects the calculated distance
• What is the speed of ultrasound in water?

  1400 meters per second
• What does the timing and distribution of echoes in ultrasound indicate?

  Health of the fetus
• How does ultrasound imaging differ from traditional imaging methods?

  It uses sound waves instead of radiation