The linear density of a string is $1\mathrm{.}610-4$ kg$/$m$.$ A transverse wave on the string is described by the equation

y $=(0\mathrm{.}026$ m$)$ sin$[(1\mathrm{.}4$ m$-4)$x $+(225-1)$t$]$

What are $($a$)$ the wave speed and $($b$)$ the tension in the string?