MCQ
A wave is propagating along $x$-axis. The displacement of particles of the medium in $z$-direction at $t = 0$ is given by: $z =$ exp$[ -(x + 2)^2]$ , where $‘x’$ is in meters. At $t = 1s$, the same wave disturbance is given by: $z =$ exp $ [ - (2 - x)^2 ]$. Then, the wave propagation velocity is
- ✓$4 m/s$ in $+ x$ direction
- B$4 m/s$ in $-x$ direction
- C$2 m/s$ in $+ x$ direction
- D$2 m/s$ in $- x$ direction

