A solid sphere of mass 1 kg and radius 1 m rolls without slipping on a fixed plane inclined at θ=30°. Two forces of magnitude 1 N each, parallel to the incline, act on the sphere, both at distance r=0.5 m from its center, as shown. The acceleration of the sphere down the plane is _____ m s⁻². Take g=10 m s⁻².