Question

A string with free boundary caused by stationary waves. The distance of four adjacent nodes is 90cm. If the speed of wave propagation is 45m/s. the frequency of the wave is...

Answer 1

$l=90cm=0.9m$

$n=4$

$\lambda=\frac{l}{n}=\frac{0.9}{4}=0.225$

$v=45\frac{m}{s}$

$\lambda=\frac{v}{f}$

$f=\frac{v}{\lambda}=\frac{45}{0.225}=200\ Hz$

$\text{Answer: }f=200\ Hz$