12-28-2021, 07:20 PM
(This post was last modified: 12-28-2021, 07:31 PM by Erik Josefsson.)
(12-28-2021, 02:52 PM)solid Wrote: Our bag is not blown up and a very small increase of the air volume inside it ΔV ≈ (Δp/p)V = 0.03 V does not increase the pressure inside (Δp=30hPa, p=1000Pa). Only a small peak when the bag adopts the new volume (its mass is not zero!) will appear. When I hit the bag with some air inside I observe a single sharp peak of about 1hPa (see the figure).
The origin of multiple peaks is still unclear.
So the first peak could maybe be interpreted as if the bag has been hit on the inside? Or even that we are actually seeing the sound of the pop hitting the phone's sensor rather than hitting the bag? Or both?
"What Does Sound Look Like?"
https://www.youtube.com/watch?v=px3oVGXr4mo
And look here! https://en.wikipedia.org/wiki/Sound_pres...d_pressure
9-inch (23 cm) diameter balloon popped with a pin[18] 0 m 1.13 kPa
9-inch (23 cm) diameter balloon popped with a pin[18] 1 m 282.5 Pa
What is that pressure sensor made of anyway? How does it work?
Best regards.
//Erik