A 10-hp, 250-V shunt motor has an armature circuit resistance of 0.5 Ω and a field resistance of 200 Ω. At no load, rated voltage, and 1200 r/min, the armature current is 3 A. At full load and rated voltage, the line current is 40 A, and the flux is 5% less than its no-load value because of armature reaction. Compute the full-load speed.