Kundt’s tube

A Kundt tube is a horizontal glass tube used in acoustics to demonstrate and measure the velocity of sound in gases. It works by creating standing waves within the tube. When a fine powder, such as cork dust, is placed inside, the motion of the air in the standing wave causes the powder to accumulate in piles at the nodes (points of no motion) and be blown away from the antinodes (points of maximum motion). This striation pattern clearly visualizes the standing wave and allows for the determination of wavelength. By combining this with the frequency of the sound, the velocity of sound can be calculated. This method was developed by German physicist August Kundt.123