Question

A $5.5m$ length of string has a mass ot $0.035kg$. If the tension in the string is $77N$, then the speed of a wave on the string will be :

• A. 102 m/s
• B. 77 m/s
• C. 110 m/s
• D. 150 m/s

Answer 1

Answer: (C)

The speed' of transverse wave in a flexible string depends upon the tension in the string and the mass per unit length of the string.
$v=\sqrt{\frac{T}{m}}$
where $T$ is tension and $m$ is mass per unit length of the string (not the mass of the string).
Given, $m=\frac{0.035}{5.5}=\frac{7}{1100}kg/m$,
$T=77N$
$\therefore v=\sqrt{\frac{77\times 1100}{7}}$
$=110m/s$