It states that the total entropy of an isolated system can never decrease over time
The instrument is a Geiger counter and is used to measure radioactive level around people's bodies.
Torque acting dowward = 6 x 0.5 = 3 Nm
Torque acting to the right = 5 x 1 = 5 Nm
5 - 3 = 2 Nm
inertia = 1/2 mr^2
0.5 x 10 x 1^2 = 5 kg-m^2
2/5 = alpha = 0.4 rad /s^2
Hope this helps