Expt. # 8, Physics 105, fall 2010 (reference only) Aim: To determine the speed of sound in air at room temperature using resonating air column (1). Apparatus: Resonance apparatus, four tuning forks, rubber mallet micrometer caliper, can of water and paper towels (1). Description of the apparatus: The apparatus consists of a 110 cm long uniform graduated glass tube of 1(1/2) diameter connected to a rubber tubing and a water reservoir supported by a stand. The level of water in the glass tube is changed by moving the attachment to the reservoir (2). Diagram of Apparatus:
Transverse wave- if the particle in a medium vibrates at right angles to the direction of propagation of a wave. It is said to be transverse wave. For example water waves and plucked strings. Longitudinal waves- If the particles in a medium vibrate parallel to the direction of propagation of a wave, it is said to be a longitudinal wave; for example speech waves.
Number of waves per second known on the frequency is represented by [In T seconds (1 second) 1 wave 1/T= f]. V= (λ/T) V= (1/T) λ V= f (λ)
If an advancing wave is obstructed it is reflected in exactly opposite direction. The advancing wave and the reflected wave interfere destructively and constructively causing nodes and antinodes.
The glass tube is filled with water to almost to the top. A tuning fork10211 Hz was excited by hitting it tangentially with a rubber mallet (rubber hammer) and the tuning fork is held at the open end as shown in the diagram and the length of the air column is slowly lowered by lowering the reservoir of the water. When the frequency of the tuning fork is the same as the air column in the glass tube resonance is heard. This is indicated by a maximum booming sound. The length of the air column is noted. The end correction 0.92...