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Sound speed calculator

L

leaky5

Lurker
Does anyone know if there is an app that can measure 2 sound points at a known distance between them and tell you the speed of an object between them.

i.e. you shoot a gun (sound point 1) at a target (sound point 2) at a distance of say 10m. Then you can work out the speed of the projectile.
 
A way, I think, would be to use an app for sound frequency measure showing in a graph.
At the graph with a time line you could measure the time between the two sound peaks.

The remainding task -to calculate with the speed of sound- could do a formular calculator or a formula in a spread sheet :)

Harry
 
Welcome to the forums!

The established way to measure a bullet's speed is with a chronograph, here's an inexpensive model -

Shooting Chrony Chronograph - The Chrony is an instrument that measures bullet velocities.

Harry, you have the right idea, the instrument you want is an oscilloscope. A PC equivalent method is described here -

Measure Bullet Speed using Audacity | ForeverGeek

Note well that shooting at metal targets is very dangerous, and personally, I would advise against it unless you have a professional range equipped with them and able to provide expert guidance on the matter.

That said, if you want such an app, here's one -

Oscilloscope Pro | AppBrain Android Market

Take distance over time, scale up to seconds to get ft/sec or meters/sec.

Another tried and true approach would be a ballistic pendulum, and then use a calculator -

Ballistic pendulum - Wikipedia, the free encyclopedia

Your safest and most accurate bet is the chronograph, fwiw.

Hope this helps!
 
Thanks for the advice.

I understand about chronograph's and the safety aspects of this. An f1 chrono costs about
 
OK, I understand better now. You have four times involved:

A= time of projectile leaving muzzle
B= time that A registered on oscilloscope
C= time of projectile on target
D= time that C registered on oscilloscope

You want C - A, but you can find that by calculating out the error of B and D using the speed of sound and known distances from the muzzle and target to the microphone.

Probably you already know that, but if not, I will be happy to assist further.

I target shoot for fun myself. :) ;)
 
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