WAVE+INTERACTIONS

WAVE INTERACTIONS What is Ultrasound?

**Ultrasound** or **ultrasonography** is a medical imaging technique that uses high frequency sound waves and their echoes. The technique is similar to the echolocation used by bats, whales and dolphins, as well as SONAR used by [|submarines]. In ultrasound, the following events happen: include component="comments" page="WAVE INTERACTIONS" limit="30"
 * 1) The ultrasound machine transmits high-frequency (1 to 5 megahertz) sound pulses into your body using a probe.
 * 2) The sound waves travel into your body and hit a boundary between tissues (e.g. between fluid and soft tissue, soft tissue and bone).
 * 3) Some of the sound waves get [|reflected] back to the probe, while some travel on further until they reach another boundary and get reflected.
 * 4) The reflected waves are picked up by the probe and relayed to the machine.
 * 5) The machine calculates the distance from the probe to the tissue or organ (boundaries) using the speed of sound in tissue (5,005 ft/s or1,540 m/s) and the time of the each echo's return (usually on the order of millionths of a second).
 * 6) The machine displays the distances and intensities of the echoes on the screen, forming a two dimensional image like the one shown below. copied from: http://www.physics.utoronto.ca/~jharlow/teaching/phy138_0708/lec04/ultrasoundx.htm

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Click the link below to open the assignment, and use the other links to help you answer the questions.


 * = **QUESTIONS** ||= **CLICK THIS LINK TO FIND THE ANSWERS** ||
 * = 2-3  ||= [[image:coachgravesawesomeclass/cat_wave.jpeg align="center" link="@http://www.kettering.edu/physics/drussell/Demos/waves/wavemotion.html"]] ||

**USE THE PHET SIM BELOW TO COMPLETE QUESTIONS 10-14** media type="custom" key="12274436" width="712" height="712" align="center"
 * = **QUESTIONS** ||= **CLICK THIS LINK TO FIND THE ANSWERS** ||
 * = **6-9**  ||= [[image:coachgravesawesomeclass/PHYSICS_CLASSROOM.jpeg align="center" link="@http://www.physicsclassroom.com/class/waves/u10l3c.cfm"]] ||