Answer
The phasors rotate at an angular speed of $~~999~rad/s$
Work Step by Step
In part (b), we found that $f_d = 159~Hz$
We can find the angular speed:
$\omega = 2\pi~f_d$
$\omega = (2\pi)~(159~Hz)$
$\omega = 999~rad/s$
The phasors rotate at an angular speed of $~~999~rad/s$
