A first-order low-pass filter has a cutoff frequency of 5 \(\mathrm{krad} / \mathrm{s}\) and a passband gain of \(20 \mathrm{~dB}\). The input to the filter is \(v(t)=10+20 \cos 5000 t+12 \cos 15 \mathrm{k} t \mathrm{~V}\). Find the rms value of the steady-state output.