A single-tank liquid-level system with inflow rate \(q_{i}\) as its input and liquid level \(h\) as its output is modeled as \(R A \dot{h}+g h=R q_{i}(t), h(0)=0\), where \(R, A, g=\) const. If the inflow rate is a unit step, find the liquid level in terms of the physical parameters. Also find the steady-state value of the liquid level.