Helping a confused particle!

Electricity and Magnetism Level 3

A positively charged particle was sitting idle at the origin of a Cartesian coordinate system. The particle is then subjected to an electric field \(\textbf{E}=E_{0}\cos\big(\frac{\pi}{2}+\omega t\big)\hat{\imath}\) at time \(t\geq0,\) where \(E_{0}\) is a positive constant scalar and \(\omega\) is the angular frequency of oscillation of electric field in \(\text{rad}/\sec.\)

What will the particle do after \(t=0?\)