What are some simple interesting ways to measure an explosion?
My school is building a new library next to the science building, and the
site prep includes several weeks of blasting to break up the granite ledge
under the site. Twice a day there is a significant explosion outside my lab
window. The blasting mats jump and the ground shakes.
(video from turkey day: https://www.instagram.com/p/BNIGIhuhn5V/)
My students love this. When the two minute warning horn sounds we all get
up and go to the window to watch.
My AP physics class is particularly interested. And now I find that
contractor is open to doing an "educational" shot sometime in the coming
week. I am looking for suggestions of things to measure. The only thing we
have planned right now is pretty simple: put something high contrast on top
of the blasting mats then use video capture to measure ∆h of the mats. We
would estimate how much mechanical energy is getting delivered to the mats
based on mat mass and mean height of jump.
The blasting company has portable seismographs that they place by all
nearby buildings (insurance, I think - your foundation cracked? not our
problem) and I hope to get access to that data. No idea what I would see,
but I'm curious. (Wave speed through the local rock?)
We have lots of vernier probes (including, now that I think of it, a
temperature probe on a very very very long cord, but I suspect the
temperature change would be small in any location where the probe had a
shot at survival)
I'd love to hear suggestions for measurements that high school students
might do to extract a little science from what is otherwise a routine
disruption.
thanks
david
___________________
David Strasburger
Physics & Astronomy teacher
Dean of New Faculty
Noble & Greenough School
10 Campus Drive • Dedham MA• 02026
(781) 320-7167