Calculating the speed of an ultrasound wave in an unknown liquid

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Homework Help Overview

The discussion revolves around calculating the speed of an ultrasound wave in an unknown liquid, using data from an oscilloscope that measures the time difference between transmitted and reflected sound waves in a tube.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the time interval between the transmitted and reflected signals, with one noting the need for consistent units. There is also an attempt to clarify the calculation of the total distance the wave travels in the tube.

Discussion Status

Some participants have provided calculations and conversions related to the time interval and distance, while others express uncertainty about the next steps. The discussion includes various interpretations of the problem setup and calculations.

Contextual Notes

Participants are working with a specific frequency and dimensions of the tube, and there is an emphasis on ensuring unit consistency in calculations. The original poster expresses a lack of clarity on how to proceed after initial calculations.

aliaze1
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Homework Statement



An ultrasound unit sends a 2.40 MHz sound wave into a 25.0-cm-long tube filled with an unknown liquid. A small microphone right next to the ultrasonic generator detects both the transmitted wave and the sound wave that has reflected off the far end of the tube. The two sound pulses are 4.40 divisions apart on an oscilloscope for which the horizontal time sweep is set to 100μs/division

What is the speed of sound in this liquid?

Homework Equations



v=d/t
v=λf

The Attempt at a Solution



Honestly, I have no clue...
 
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The microphone detects the transmitted and reflected wave.

Time interval between signals (transmitted and reflected pulses) is 4.4 div * 100μs/division or _________ μs?

The wave had to travel 2 lengths (down and back) of a 25 cm tube in that time. Make sure units are consistent.
 
THANK YOU! GREATLY APPRECIATED!

i had figured that it was 440μs but didnt know where to go from there...

THANKS ONCE AGAIN!
 
As reference to anyone else who may need this problem:

50cm = 0.5m
4.3 divisions * 100μs/division = 440μs
440μs = 4.4*10^-4 seconds

0.5/(4.4*10^-4) = 1136.363636363636363636... m/s
 

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