posted by HelpMeWithPhysics .
A violin string is 33cm long. The thinnest string on the violin is tuned to vibrate at a frequency of 659Hz.
(a) What is the wave velocity in the string?
(b) If you place your finger on the string so that its length is shortened to 28cm, what is the frequency of the note that the string produces?
λ =2•L = v/f.
v = 2•L•f = 2•0.33•659 = 465 m/s.
λ1 =2•L1 = v/f.
f = v/ 2•L1 = 465/2•0.28 =776.7 Hz.