The displacement of a plane progressive wave in a medium, travelling towards positive x-axis with velocity 4 m/s at t = 0 is given by \(\rm {y}=3 \sin 2 \pi\left(-\frac{x}{3}\right)\). Then the expression for the displacement at a later time t = 4 sec will be
1
\(\rm {y}=3 \sin 2 \pi\left(-\frac{x-16}{3}\right)\)
2
\(\rm {y}=3 \sin 2 \pi\left(\frac{-x-16}{3}\right)\)
3
\(\rm y=3 \sin 2 \pi\left(\frac{-x+1}{3}\right)\)
4
\(\rm {y}=3 \sin 2 \pi\left(\frac{-x-1}{3}\right)\)