In the block diagram shown below, an infinite tap FIR filter with transfer function \( H(z) = \frac{Y(z)}{X(z)} \) is realized. If \[ H(z) = \frac{1}{1 - 0.5z^{-1}}, \] the value of \( \alpha \) is \(\underline{\hspace{2cm}}\) 



The time delay between the peaks of the voltage signals \( v_1(t) = 2\cos(6t + 60^\circ) \) and \( v_2(t) = -3\sin(6t) \) is ____ s.