A model of a persons arm is used for ergonomics studies. Distances are rAB = 45 cm, rBC 28 cm, and rCD = 19 cm. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. The shoulder of the persons arm is labeled A. The elbow is labeled B. The wrist is labeled C. The tip of the index finger is labeled D.A horizontal line from point A to the right is labeled y. A vertical line from point A below is labeled x. The angle between the vertical line x and line AB to the right of the vertical line x is 30 degrees. The vertical line, labeled 3, from the positively sloped line BC ends at the right end of the horizontal line, labeled 4, from the positively sloped line BC. The sloped line CD makes an angle of 25 degrees above the horizontal. Express r->AD using polar vector representation, measuring orientation positive counterclockwise from the right-hand horizontal direction. (Round the final answers to four decimal places. Include a minus sign if necessary.)