Instructions: As you did with Cycle I, you need to answer
each of the following questions TYPED and offer experimental
evidence for your answers. The bold type
doesn’t need to be answered. It is just
the topic question. The lettered
questions are what need to be answered (IN RED TYPE)
1. How does the
length of the vibrating material affect the frequency of the sound produced?
a. How is the length of a tuning fork related to the frequency?
2. How does the vibration length affect the
pitch of the sound produced?
a. What is
vibrating when you tap a bottle and blow into a bottle? IT IS DIFFERENT
(tapping vs. blowing. So, Be Careful).
b. What is vibrating
when you blow into a straw?
c. What is vibrating when
you hit a chime?
d. What is vibrating
when you pluck a meter stick?
e. What is vibrating when you rub the rim of
the water goblets?
3. Under what circumstances will a vibrating
object cause another object to vibrate?
a. What two ways can this energy be transferred?
b. When does each of these ways happen?
4. What relationship exists between the
frequencies that produce standing waves in a tightly held spring?
a. What did
you have to do to the frequency with which you shook the spring to increase the
number of standing waves?
b. What relationship exists between the frequencies that produce standing waves in an open-end flute (in other words, what did you have to physically do to get different frequencies out of the pipe)?
c. What relationship
exists between the frequencies that produce standing waves in a closed end
flute?
5. Compare the fundamental frequencies in
equal length open and closed end pipes.
a. Come up with a mathematical formula so
that if you know the length of an open
pipe (from the tip of the mouthpiece
to the end of the pipe – in meters), you can predict the fundamental
frequencies. (HINT #1: you will
need to remember that the speed of sound in air is 345 m/sec. HINT #2:
The mathematical formula will be DIFFERENT for EACH
fundamental/harmonic. You must come up
with formulas for fundamental/harmonics #1 thru #4. HINT#3: You should
collect the fundamental frequencies #1 thru #4 on the Logger Pro (activity D4)
and work backwards until you can reach the length of your pipe in
METERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)
b. Come up with a mathematical formula so that if you know the
length of a closed pipe (from tip to end) you can predict
the fundamental frequencies. Same hints
apply as above, only do this with a closed pipe. The length of the pipe will be the same as the open pipe of
course.
All total you will have 8
formulas for this question.
Closed Pipe:
f1= f2=
f3= f4=
6. What causes various instruments to sound different when playing the same note? (yes, I know it is bold type. But just answer the darn question!).