A pendulum consists of a small object hanging from the ceiling at the end of a string of negligible mass. The string has a length of0.75m. With the string hanging vertically, the object is given an initial velocity of1.6m/s parallel to the ground and swings upward in a circular arc. Eventually, the object comes to a momentary halt at a point where the string makes an angle with its initial vertical orientation and then swings back downward. Find the angle .