A guitarist wishes to tune the B-string to match a standard tuning fork that vibrates at
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
A guitarist wishes to tune the B-string to match a standard tuning fork that vibrates at 440Hz. The following observations are recorded.
• With the string at its initial tension, the player hears five beats each second when the string and the fork sound together.
• After tightening the string slightly, the beat rate increases to seven beats per second.
Use this information to analyze the string’s tuning.
(a) State the two possible frequencies the string could have had before it was tightened, based solely on the initial beat rate.
(b) Explain how the change in beat frequency after tightening identifies which of the two possibilities from part (a) is correct.
(c) Determine the original frequency of the string before it was tightened.