Class II Transformer - 12 Volt AC, 40 VA, UL/CSA Approved : MGT-1240

Could I use this transformer plugged into a zwave adapter to trigger a standard a 30A alarm siren?

Is there a way to know which screw is positive and which one is negative

I am trying to get power to this antenna motor for a diy automatic door opener on my chicken coop. will this work to power this motor radiotronics hd

How many mh is this?