A tractor PTO shaft, through a spur-gear reduction, drives a small grain auger at 540 rpm. The driving gear on the PTO shaft has 0.18 m pitch circle diameter. The auger requires 3.5 kW, transmitted through this gear. Normal force along the line of action between the meshing teeth is 760 N. Assume involute spur gears, single tooth contact, and neglect friction. The pressure angle (in degrees) is ________.
(Rounded off to two decimal places)
(Take π = 3.14)