A Vibrating Tuning Fork of 850 Hz Is Held Above $\Delta$

question 8

Multiple Choice

A vibrating tuning fork of 850 Hz is held above a tube filled with water.The first and third resonances occur when the water level is lowered by 8.8 cm and 47.6 cm from the top of the tube.If there is a small end correction that adds a small extra length $\Delta$ L to the effective length of the air column,calculate $\Delta$ L.Assume the speed of sound to be 330 m/s.

• A)0.2 cm
• B)0.9 cm
• C)0.4 cm
• D)0.6 cm
• E)1.1 cm