Ultrasound

• Ultrasound

  Refers to the range of sound waves that have frequencies above human hearing
• Can humans hear ultrasounds

  No
• Are there animals that can hear ultrasounds

  Yes like bats
• What do bats use ultrasound for

  Communication and echolocating
• What device can we use to generate ultrasound

  A speaker
• Is ultrasound harmful

  No
• What is partial reflection

  When only some of the waves are reflected, while other waves are absorbed or transmitted
• How can ultrasound waves be used to detect the thickness of different mediums within an object

  Reflects off of the boundaries between mediums of different densities

  The waves speed and the time it takes to bounce back to the receiver can be used to calculate the thickness of each medium
• How can ultrasound waves be used to detect cracks in an object

  Ultrasound would reflect off of the edge of the crack and can be detected back at the receiver sooner that expected
• What is sonar

  A technique that uses ultrasound waves to navigate, measure distances, communicate, and detect objects.

  Often used underwater
• How can sonar be used to calculate the distance between a submarine and the sea floor

  The submarine can emit an ultrasound wave and measure the time it takes to return. It can then use the speed of the wave and time taken to calculate the distance