Lab Report 2
Experiment #2 Resonance of Air Columns
Connie Wang
PHYS 2426 – 103
Partners: Deneen Ernst, Dalton Penn, and Trey Thompson
DATA__________________________________________________________________________________________
Room Temperature: 21°C Theoretical speed of sound: 343 m/s
Experimental speed of sound (average): 348 m/s Percent Difference: + 1.46%
Frequency of Tuning Fork (Hz) | First Position of Resonance | Second Position of Resonance | Wavelength (m) | Velocity of Sound (m/s) | | 1 | 2 | 3 | Average (cm) | 1 | 2 | 3 | Average (cm) | | | 512 | 15.8 | 15.3 | 15.5 | 15.5 | 49.2 | 49.4 | 49.1 | 49.2 | 0.674 | 345 | 384 | 21.0 | 21.2 | 20.9 | 21.0 | 67.1 | 66.2 | 66.1 | 66.5 | 0.910 | 349 | 320 | 25.2 | 25.4 | 25.1 | 25.2 | 79.4 | 79.5 | 79.7 | 79.5 | 1.090 | 349 |
CALCULATIONS
Calculation 1: Determining wavelength with frequency.
12λ=L2-L1
12λ512=0.492 m-0.155 m
λ512=0.674 m λ384=0.910 m λ320=1.090 m
Calculation 2: Determine the velocity of sound in air with frequency; find average.
v=fλ v=512 Hz0.674 m
v512=345ms v384=349ms v320=349ms vavg=348ms Calculation 3: Find the velocity of sound in air from the room temperature. v=331msT273 v=331ms21+273273
v=343 m/s
Calculation 4: Percent difference
% difference=actual-theoreticaltheoreticalx 100
% difference=348-343343x 100
% difference=+1.46 %
QUESTIONS 1. If the room temperature for this experiment had been lower, the length of the resonating air column would have been shorter. The length of air column is directly proportional to temperature due to v=331msT273 . 2. An atmosphere of helium would cause an organ pipe to have a higher pitch because the speed of sound is faster in helium, but since the pitch of a tuning fork has a set frequency, the pitch will not change. 3. If you measure an interval of 5 seconds between seeing a lighting flash and hearing the thunder with the temperature of air being 20°C,
Connie Wang
PHYS 2426 – 103
Partners: Deneen Ernst, Dalton Penn, and Trey Thompson
DATA__________________________________________________________________________________________
Room Temperature: 21°C Theoretical speed of sound: 343 m/s
Experimental speed of sound (average): 348 m/s Percent Difference: + 1.46%
Frequency of Tuning Fork (Hz) | First Position of Resonance | Second Position of Resonance | Wavelength (m) | Velocity of Sound (m/s) | | 1 | 2 | 3 | Average (cm) | 1 | 2 | 3 | Average (cm) | | | 512 | 15.8 | 15.3 | 15.5 | 15.5 | 49.2 | 49.4 | 49.1 | 49.2 | 0.674 | 345 | 384 | 21.0 | 21.2 | 20.9 | 21.0 | 67.1 | 66.2 | 66.1 | 66.5 | 0.910 | 349 | 320 | 25.2 | 25.4 | 25.1 | 25.2 | 79.4 | 79.5 | 79.7 | 79.5 | 1.090 | 349 |
CALCULATIONS
Calculation 1: Determining wavelength with frequency.
12λ=L2-L1
12λ512=0.492 m-0.155 m
λ512=0.674 m λ384=0.910 m λ320=1.090 m
Calculation 2: Determine the velocity of sound in air with frequency; find average.
v=fλ v=512 Hz0.674 m
v512=345ms v384=349ms v320=349ms vavg=348ms Calculation 3: Find the velocity of sound in air from the room temperature. v=331msT273 v=331ms21+273273
v=343 m/s
Calculation 4: Percent difference
% difference=actual-theoreticaltheoreticalx 100
% difference=348-343343x 100
% difference=+1.46 %
QUESTIONS 1. If the room temperature for this experiment had been lower, the length of the resonating air column would have been shorter. The length of air column is directly proportional to temperature due to v=331msT273 . 2. An atmosphere of helium would cause an organ pipe to have a higher pitch because the speed of sound is faster in helium, but since the pitch of a tuning fork has a set frequency, the pitch will not change. 3. If you measure an interval of 5 seconds between seeing a lighting flash and hearing the thunder with the temperature of air being 20°C,