You may change your mind as often as you wish. When you are satisfied with your
responses, click the SUBMIT button at the bottom of this page. Don't submit more
than once. (If you absolutely HAVE to
resubmit it, put a note on the end to that effect.)
Why are
there no dead spots in the sound distribution when either the left or the right source is transmitting but there are
multiple dead spots when both sources are
transmitting? Do the dead spots depend on how far apart the sources (red dots)
are?
2.
In 1976, the Who set a record for the loudest concert: the sound
level 46 m in front of the speaker system was 120 dB, the pain threshold.
A wise physics student decided to sit further back to reduce the
sound level to a more tolerable 90 dB. How far from the speakers did
they have to move?
49 m
76 m
138 m
about a mile
3.
When two sound waves have different frequencies, they add much
the way two waves on a string add together. Playing two keys on
a piano that are adjacent to each other makes a dissonant chord
with a wavering sound. The "wavering" is called "beats". Use the
following Physlet to determine how close the two frequencies are.
The above simulation shows a superposition of two waves on identical strings (position in meters and time is in seconds). What is the difference in frequency between the two waves? Start
honors extra
In the wild west legend tells us, Indians were known to press their ear to the
ground to detect oncoming cavalry. (Obviously they never went to
Who concerts.) A well trained indian could even tell how far away
the cavalry/Buffalo herd was. Can you think of a Physics reason for this
mysterious ability?
Below is a space for your thoughts, including general comments
about today's assignment (what seemed impossible, what reading didn't make
sense, what we should spend class time on, what was "cool", etc.):
You may change your mind as often as you wish. When you are satisfied with your responses,
click the SUBMIT button.
I received no help from anyone on this assignment.
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