Suppose you sound a 1056-Hz tuning fork at the same time you strike a note on the piano and hear 2 beats/second.  You tighten the piano string very slightly and now hear  3 beats/second.  What is the final frequency of the piano string?  Be Certaion to briefly explain your answer.

Solution2 :At 2 beats/second, the piano must originally be at either 1058 Hz or 1054 Hz. The 2 beats/sec is the differece between the tuing fork and the piano string. Tightening the string raises the frequency, since you now hear 3 beat/sec, the new frequency is 1059 Hz.