Mandatory Experiments: Sound Flashcards
ME 1: To measure the speed of sound in air: Describe how first position of resonance was found. Why was it necessary to measure the diameter of the air column?
Hold vibrating tuning fork over an open end of the tube which is completely submerged.
Raise tube out of water increasing length of column of air until first resonance between tuning fork and column of air is observed by hearing.
Because wave exists partially above top of tube and end correction must be calculated.
ME 1: To measure the speed of sound in air: If the first and second positions of resonance are known, how can speed of sound be calculated? Formula,
- Find distance between first two positions of resonance.
- Double this distance for wavelength.
- Multiply wavelength by frequency (v = f x lambda)
v = 4f(l + 0.3d)
ME 2: Fundamental frequency of stretched string with length: Adjustments for graph. State relationship. How does graph verify?
Frequency on y-axis and 1/length on x-axis
frequency inversely proportional to length
Straight line through origin
ME 2: Fundamental frequency of stretched string with length: How do you use the graph to find the mass per unit length.
f = 1/2l x (root of tension/root of mass per unit length)
Mass per unit length = Tension / 4 x (Slope squared)
ME 3: Fundamental Frequency of stretched string with tension: How was tension measured? How was length measured? How was fundamental frequency determined? How did student use the apparatus?
Newton balance.
Metre stick, length between bridges.
Change tuning fork and read off value.
Held tuning fork to string and varied tension, paper rider fell off when resonance occurs.
ME 3: Fundamental Frequency of stretched string with tension: How did the student know that the string was vibrating at its fundamental frequency? Graph adjustments. Formula for mass per unit length calculation.
Paper rider fell off the string.
Frequency on y-axis, root tension on x-axis.
Mass per unit length = 1/4(length squared) x 1/(slope squared)
