A piano wire 0.5m long has a total mass of 0.01kg and is stretched with a tension of 800N. Calculate the frequency of the wire when it sounds its fundamental note
A
200Hz
B
100Hz
C
4Hz
D
2Hz
Verified Correct Answer: A.
Physical Principles & Numerical Solution
F = \(\frac{1}{2L}\)\(\sqrt\frac {T}{m}\)
N:B m is mass per length
= \(\frac {0.01}{0.5}\)
= 0.02kgm-1
F = \(\frac{1}{2\times 0.5}\)\(\sqrt\frac {800}{0.02}\)
= 200Hz
Source: Myschool Past Questions Archive (Record #28380)