2 When a perubulum 0.5 m long swings back and forth, its angular displacement & from rest position, in radians, is given by e(0)= I .where f is the time. in scoonds. At what time(s) during the first 4 4 is the pendulum displaced I em vertically above its rest position? (Assume the pendulum is at its rest position at / = 0) v