The diagram shows a displacement-distance graph for a transverse wave travelling to the right along a stretched string.
What is the phase difference between point P P\,P and point Q Q\,Q on the wave?
π3 rad\frac{\pi}{3}\text{ rad}3π rad
2π3 rad\frac{2\pi}{3}\text{ rad}32π rad
5π6 rad\frac{5\pi}{6}\text{ rad}65π rad
4π3 rad\frac{4\pi}{3}\text{ rad}34π rad