$($b$)$ A $2-$ D wave tank has a still water depth of $2m$ and $1\mathrm{.}25m$ wide. A wave generator produces monochromatic waves that when measured at wave gauge installed has $0\mathrm{.}60m$ height and period of $2\mathrm{.}8$ seconds. Calculate the wave length, celerity, group velocity, energy.