COMD 5070 Exam Three: Questions With In-
Depth Solutions
What is the nature of science? Correct Answer - The scientific
approach involves collecting data so that we can understand the
given phenomenon from our own direct experience.
Science is empirical. What does that mean? Correct Answer -
Based on data, collect data and interpret data.
Science is deterministic. What does that mean? Correct Answer -
Obeys physical laws.
Science is predictive. What does that mean? Correct Answer -
If you do this... then that will happen.
Science is parsimonious. What does that mean? Correct Answer -
Uses the most straightforward explanation possible.
What is a transverse wave? Correct Answer - A wave that
travels across the surface of a medium, such as water.
What is an example of a transverse wave? Correct Answer - -
Pebbles in a pond cause circular ripples that would cause a toy boat
in the water to bob up and down, the water itself doesn't move, but
the wave moves.
- A wave in a stadium.
What is a longitudinal wave? Correct Answer - A local change
in tension, causing pressure compressions and rarefactions.
What is an example of a longitudinal wave? Correct Answer - A
slinky.
,How does sound transmit through air? Correct Answer - -
Vibrations will travel through the air as the molecules move back &
forth-air molecules move right left & right multiple times in a
vibrating pattern.
- The molecule next to the item that made the sound is not the one
going all the way into the ear.
- Molecules push/pull their neighboring air molecules.
- The vibration then travels, (because it's carried on through the
molecules) not the molecules themselves as they return back to
their original home and vibrate around their home position.
Can sound travel through the vacuum of space? Correct Answer -
No.
What is a period? Correct Answer - - In seconds is 1/frequency
in Hz.
-The amount of time it takes for 1 full oscillation to occur (going
from displacement away from resting position
beyond resting position to the negative side and back to rest).
-It is the opposite of frequency.
What is the frequency? Correct Answer - - In Hz is 1/period in
seconds.
-How often the air molecules vibrate (how often they leave and
return back home).
- Measured in Hz. 1 Hz means
1 oscillation or 1 vibration per second.
How to calculate the period? If there is a 250 Hz sine wave, what is
the period? Correct Answer - 1/250= 0.004.
How to calculate frequency? If there is a period of 2ms (0.002
seconds)? Correct Answer - 1/0.002= 500 Hz.
, What is a harmonic series? Correct Answer - When multiple
sine waves or pure tones are combines together.
What are integer multiples? Correct Answer - The whole
number multiples of whatever the fundamental frequency is.
What is the fundamental frequency? Correct Answer - The
lowest frequency in a series that we will combine to make a
harmonic series.
How does sound transmit when the medium changes? Correct
Answer - -Sound will travel the most readily through a medium
that is continuous, that does not change in its properties from one
place to another.
- Air is a medium.
- Air molecules oscillate with sound.
- Energy transmits through similar mediums.
- Change of medium will change if the sound is reflected or
transmitted.
- Talking to a submerged swimmer: medium changed & now you
have to speak up, more sound is being reflected than transmitted.
- Reflection can happen where tube size changes.
How are decibels added? Correct Answer - You always go up 6
dB when you add two identical intensities.
What is 20 dB + 20 dB? Correct Answer - 26 dB.
What is 50 dB + 50 dB? Correct Answer - 56 dB.
What is an octave? Correct Answer - A doubling of Hz.
Depth Solutions
What is the nature of science? Correct Answer - The scientific
approach involves collecting data so that we can understand the
given phenomenon from our own direct experience.
Science is empirical. What does that mean? Correct Answer -
Based on data, collect data and interpret data.
Science is deterministic. What does that mean? Correct Answer -
Obeys physical laws.
Science is predictive. What does that mean? Correct Answer -
If you do this... then that will happen.
Science is parsimonious. What does that mean? Correct Answer -
Uses the most straightforward explanation possible.
What is a transverse wave? Correct Answer - A wave that
travels across the surface of a medium, such as water.
What is an example of a transverse wave? Correct Answer - -
Pebbles in a pond cause circular ripples that would cause a toy boat
in the water to bob up and down, the water itself doesn't move, but
the wave moves.
- A wave in a stadium.
What is a longitudinal wave? Correct Answer - A local change
in tension, causing pressure compressions and rarefactions.
What is an example of a longitudinal wave? Correct Answer - A
slinky.
,How does sound transmit through air? Correct Answer - -
Vibrations will travel through the air as the molecules move back &
forth-air molecules move right left & right multiple times in a
vibrating pattern.
- The molecule next to the item that made the sound is not the one
going all the way into the ear.
- Molecules push/pull their neighboring air molecules.
- The vibration then travels, (because it's carried on through the
molecules) not the molecules themselves as they return back to
their original home and vibrate around their home position.
Can sound travel through the vacuum of space? Correct Answer -
No.
What is a period? Correct Answer - - In seconds is 1/frequency
in Hz.
-The amount of time it takes for 1 full oscillation to occur (going
from displacement away from resting position
beyond resting position to the negative side and back to rest).
-It is the opposite of frequency.
What is the frequency? Correct Answer - - In Hz is 1/period in
seconds.
-How often the air molecules vibrate (how often they leave and
return back home).
- Measured in Hz. 1 Hz means
1 oscillation or 1 vibration per second.
How to calculate the period? If there is a 250 Hz sine wave, what is
the period? Correct Answer - 1/250= 0.004.
How to calculate frequency? If there is a period of 2ms (0.002
seconds)? Correct Answer - 1/0.002= 500 Hz.
, What is a harmonic series? Correct Answer - When multiple
sine waves or pure tones are combines together.
What are integer multiples? Correct Answer - The whole
number multiples of whatever the fundamental frequency is.
What is the fundamental frequency? Correct Answer - The
lowest frequency in a series that we will combine to make a
harmonic series.
How does sound transmit when the medium changes? Correct
Answer - -Sound will travel the most readily through a medium
that is continuous, that does not change in its properties from one
place to another.
- Air is a medium.
- Air molecules oscillate with sound.
- Energy transmits through similar mediums.
- Change of medium will change if the sound is reflected or
transmitted.
- Talking to a submerged swimmer: medium changed & now you
have to speak up, more sound is being reflected than transmitted.
- Reflection can happen where tube size changes.
How are decibels added? Correct Answer - You always go up 6
dB when you add two identical intensities.
What is 20 dB + 20 dB? Correct Answer - 26 dB.
What is 50 dB + 50 dB? Correct Answer - 56 dB.
What is an octave? Correct Answer - A doubling of Hz.
