An object attached to a coiled spring is pulled down a distance of 11 centimeters from its rest position and then released. Assuming that the motion is simple harmonic with a period of 2 seconds, write an equation that relates the displacement d of the object from its rest position after t seconds. Also assume that the positive direction of the motion is up. At time t = 0 the object is at its resting position and moving down. (I) An equation that models the motion of the object is E. (Type an equation. Use integers or fractions for any numbers in the equation.)