#### Answer

The angular momentum is $-0.025~kg~m^2/s$.

#### Work Step by Step

We can express the angular velocity in units of rad/s. Note that the angular velocity is negative since the rotation is in the clockwise direction.
$\omega = -(600~rpm)(\frac{2\pi~rad}{1~rev})(\frac{1~min}{60~s})$
$\omega = -20\pi~rad/s$
We can find the moment of inertia of the disk.
$I = \frac{1}{2}MR^2$
$I = \frac{1}{2}(2.0~kg)(0.020~m)^2$
$I = 4.0\times 10^{-4}~kg~m^2$
We can find the angular momentum about the axle.
$L = I~\omega$
$L = (4.0\times 10^{-4}~kg~m^2)(-20\pi~rad/s)$
$L = -0.025~kg~m^2/s$
The angular momentum is $-0.025~kg~m^2/s$.