To solve this problem it is only necessary to apply the kinematic equations of angular motion description, for this purpose we know by definition that,

Where,
Angular Displacement
Angular Acceleration
Angular velocity
Initial angular displacement
For this case we have neither angular velocity nor initial angular displacement, then

Re-arrange for 

Replacing our values,


Therefore the ANgular acceleration of the mass is 
Explanation:
A compass needle acts as a Magnet
<span>The law of conservation of energy applies to a light bulb because the energy is being transformed into light and the light bulb is acting as a catalyst. The light bulb itself is not a form of energy, however when in combination with the electrical outlet to the bulb the electricity heats up the metal interior forming it into light. according to the law of conservation energy cannot be created or destroyed, but instead is formed into different kinds of energy. In relation to a light bulb electrical currents are forming heat energy by heating up the metal interior, then the bulb or glass around it allows to radiate light.</span>
A scientific journal article that is peer reviewed. This is because it is more likely not have factual information and sources to that information.