Mousetraps, like the one shown in in the figure, rely on torsion springs. Torsion springs obey the rotational analogue of Hooke's law.

=−

In the equation, is the torque, is the torsion spring constant in units of newton–meters per radian, and is the angular displacement of the torsion spring from equilibrium.

If the value of the torsion spring constant is =0.145 N·m/rad and just enough torque is applied to move the trap arm at a constant speed through radians, how much work is done to set the trap?