An object performs simple harmonic motion with amplitude 0.12m and period 2.0s. The displacement at t=0 is unspecified. The object first passes through the equilibrium position (x=0) at t=0.50s while moving in the +x direction. Determine the phase constant ϕ (in radians) for the displacement written as x(t)=Acos(ωt+ϕ), where ϕ is to be given within the interval −π to π (endpoints included).