Speed of Sound
ASSUMPTION UNIVERSITY
Faculty of Engineering
Physics Laboratory I
1. EXPERIMENT : Speed of sound 2. OBJECTIVE: : (1) To determine the wavelength of a sound in resonance air column. (2) To determine the speed of sound in air at room temperature.
3. APPARATUS : Resonance tube (air column) attached with water container and meter stick, thermometer, function generator, speaker.
4. THEORY: : Sound is a longitudinal wave in a medium.
If n is the frequency and is the wavelength of the standing wave, than the speed of the sound at the temperature t c is given by:
vt = (1)
Wavelength (ג)
The speed of sound in air at 0 °C is 331.5 m/s, and as the temperature rises it increases at the rate of about 60 cm/s per degree centigrade. Hence the speed of sound vt at temperature t is obtained from the speed v0 at 0 °C by the relation
vt = v0 + 0.6 t (m/s) (2) vt = [ 331.5 + 0.6 t ] (m/s)
5. INSTRUCTIONS
1. Record the frequency of speaker (source of vibrating object) from the function generator.
2. Record the temperatures of the room in the region near your apparatus.
3. Fill the water in to the glass tube (column) nearly full.
4. Switch on the function generator and while holding the speaker at the top of the air column.
5. Adjust the water level for the shortest length of the air column, which gives a maximum resonant sound (very loud sound). [Raising and lowering the attached reservoir R can adjust the water level or length of air column.] Mark the point and move the water level past the mark a few times to check the correctness of the position selected.
6. Measure the distance of top of the tube to the first resonance position
Faculty of Engineering
Physics Laboratory I
1. EXPERIMENT : Speed of sound 2. OBJECTIVE: : (1) To determine the wavelength of a sound in resonance air column. (2) To determine the speed of sound in air at room temperature.
3. APPARATUS : Resonance tube (air column) attached with water container and meter stick, thermometer, function generator, speaker.
4. THEORY: : Sound is a longitudinal wave in a medium.
If n is the frequency and is the wavelength of the standing wave, than the speed of the sound at the temperature t c is given by:
vt = (1)
Wavelength (ג)
The speed of sound in air at 0 °C is 331.5 m/s, and as the temperature rises it increases at the rate of about 60 cm/s per degree centigrade. Hence the speed of sound vt at temperature t is obtained from the speed v0 at 0 °C by the relation
vt = v0 + 0.6 t (m/s) (2) vt = [ 331.5 + 0.6 t ] (m/s)
5. INSTRUCTIONS
1. Record the frequency of speaker (source of vibrating object) from the function generator.
2. Record the temperatures of the room in the region near your apparatus.
3. Fill the water in to the glass tube (column) nearly full.
4. Switch on the function generator and while holding the speaker at the top of the air column.
5. Adjust the water level for the shortest length of the air column, which gives a maximum resonant sound (very loud sound). [Raising and lowering the attached reservoir R can adjust the water level or length of air column.] Mark the point and move the water level past the mark a few times to check the correctness of the position selected.
6. Measure the distance of top of the tube to the first resonance position