Under constant tension and constant mass per unit length, the note produced by a plucked string is 500Hz when the length of the string is 0.90m. At what length is the frequency 150Hz?
-
A.
3m -
B.
4m -
C.
5m -
D.
6m
Correct Answer: Option A
Explanation
F = (frac{1}{2L})(sqrtfrac{T}{m})
F1L1 = F2L2
500 x 0.9 = 150 x L2
therefore, L2 = 3m