Accurately determine the average speed of sound in air with this elegant activity! Striking a tuning fork and holding it over the open end of a tube filled with water, students slowly lift the tube and tuning fork out of the water until they “hear” the resonance. They then measure the length of the tube above the water’s surface, and use this value to calculate the wavelength and speed of sound. Simple activity is easy to do and yields great results—average percent error is less than 2%. Discovering the Speed of Sound in Air kit comes with the necessary tubes and rubber stopper for one group of students, while the classroom set includes enough materials for eight groups of students. Each kit comes complete with student activity sheets, detailed Teacher Notes, and sample data. The experiment requires the use of a tuning fork set ranging from 256 Hz to 512 Hz, which can be shared among student groups. Tuning fork set is sold separately. A support stand and two extension clamps are also needed but not included.