# in a stretched string the speed of wave is 20m/s ` frequency 50hz . the find the phase difference in vibration of two point at string situate 10cm

$\lambda=\frac{v}{\nu}=\frac{20}{50}=0.4=40cm$
$\Delta \phi=\frac{2\pi}{\lambda}\times\Delta x=\frac{2\pi}{40}\times10=\frac{\pi}{2}$