Materials:Tuning fork, plastic tube and ruler.

1. Take a tuning fork and gently hit one of its arms against a book (Hit it against a hard object and you will damage the fork!). You will hear a zoom of frequency f =number of cycles per second (written as a number at one arm or at the base of the fork). The wavelength and the frequency of sound satisfy

                                                                        (wavelength)x(frequency) = v = speed of sound

Submerge one end of the tube in a sink with enough water to immerse about half of the tube and place the vibrating fork near the other end. Lower the tube inside water until you to hear a loud sound. It is advisable to continue beyond the first sign of resonance to make sure that you are hearing the loudest sound.

2. Now measure the length L of the tube that is above water. At resonance, the wavelength is approximately 4L. Use this result and the formula above to find the speed of sound v.

3. Repeat the experiment four times to find the average sound velocity and its uncertainty. Are the variations between trials significant?