Question

A string of length $7\text{m}$ has a mass of $0.035\text{kg}$. If the tension in the string is $60.5\text{N}$, then speed of a wave on the string is:

• A. $77\text{m/s}$
• B. $102\text{m/s}$
• C. $110\text{m/s}$
• D. $165\text{m/s}$

Answer 1

The correct option is C $110\text{m/s}$

We know that
Velocity of wave $v=\sqrt{\frac{T}{\mu }}$
$\Rightarrow v=\sqrt{\frac{T}{\left(\frac{m}{l}\right)}}$
$\Rightarrow v=\sqrt{\frac{Tl}{m}}=\sqrt{\frac{60.5\times 7}{0.035}}$
​​​​​​​$\therefore v=\sqrt{12100}=110\text{m/s}$