$(3)$ Do inverse Laplace transformation for the given s domain functions, and find the steady state response of the given systems.

$($a$)$ The output $Y(s)($with a step input$)$ is

$Y(s)=\frac{15(s+1)}{s(s+7)(s+2)}.$

$($b$)$ The rotational velocity $W(s)$ is

$(s)=\frac{2(s+4)}{(s+5)(s+1{)}^2}\frac{1}{s}.$