The transfer function of a system is given by
$$G(s)=\frac{e^{-s/500}}{s+500}$$
The input to the system is $x(t)=\sin100\pi t$. In periodic steady state the output of the system is found to be $y(t)=A\sin(100\pi t-\phi).$ The phase angle $(\phi )$ in degree is ___________.