Well, today we had our first quiz.
Not only should it have not been a surprise for anybody who was there, but it should have been pretty easy considering it was based largely on the previous homework assignment, and almost identical to the review sheet I passed out on Friday.
Nonetheless, I know some students still haven't learned the basic terms/ideas that have been presented to them over the past few weeks.
So, now is a GREAT time to do something about it.
I am at school for generally 2 hours longer than you are. Before and after. And 5th period lunch is generally open for me (room 35 across the hall). So, please take some initiative if you are struggling. It is easier to get you back on track soon, than to wait and have a catastrophe on your hands later.
After the quiz we talked about two things.
1) refraction
2) resonance patterns (harmonics) on strings and in tubes.
First, refraction.
As waves change material, they change speed.
Since the frequency stays the same, the wavelength changes.
If this happens in water/air or with light at AN ANGLE, then the wave will enter the new material at a different angle. This process is called "refraction".
We looked at a simulation to help us visualize this.
Change the setup to Refraction (about halfway down the list).
You can also look at this explanation:
or check your textbook for more help.
We also examined standing wave patterns on strings. These different resonance patterns are called "harmonics" by music people.
The basic "types" of resonators we have are:
string - fixed at both ends
tube - open at one end
tube - open at both ends
the open ends would have anti-nodes, the fixed/closed ends would have nodes.
We looked at the basic progression of standing waves, such as you see in the picture here, which is from this site: http://www.phys.unsw.edu.au/~jw/flutes.v.clarinets.html and is discussing flutes (open-open) vs. clarinets (open - closed).
here's some technical junk on it: http://hyperphysics.phy-astr.gsu.edu/hbase/waves/string.html
but this might be easier to look at:
and
and again, your book is a good source for this stuff.
1 comment:
MISTER SCHUETZ!!!
you need to update this more often so i can remember what we did today. and yesterday.
and this is an old icky post.
okay i'll see you on friday!!
-nina S /// period 1
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