Speed of sound James, a grade 12 student, completed a lab activity to find the speed of sound in air using a closed-air column. He measured the...

1. Speed of sound

James, a grade 12 student, completed a lab activity to find the speed of sound in air using a

closed-air column. He measured the temperature of the room to be 21 °C. Using a tuning fork

with a frequency of 1040 Hz, he obtained the following resonant lengths for the closed air column:

Observations:

L

1 = 7.4 cm

L

2 = 22.5 cm

L

3 = 36.7 cm

Questions:

a) Use the resonant lengths to do three calculations to find the wavelength. Find the average

wavelength and use that in further calculations.

b) Using the wave equation, what is the speed of sound in the air column?

c) What is the theoretical speed of sound in the room according to the temperature?