It doesnвЂ™t matter what you choose as a coordinate system, only that you explicitly choose one. Of course, choosing the zero at the location at which the object was dropped, the positive direction as down, and the scale in feet is also perfectly acceptable. Using this coordinate system, the position of the object could have been specified at any particular instant of time. A coordinate system is comprised of a zero, a specified positive direction, and a scale.ДЇor example, in the hypothetical experiment in which the object was dropped from shoulder height, a coordinate system could have been defined in which the zero position was at ground level, the positive direction was up, and the scale used was meters. Without a specified coordinate system, position is a meaningless concept. The position of an object is its location relative to a well-defined coordinate system at a particular instant of time. Specifying these three parameters at all times forms a complete description of the motion of an object. Three parameters are carefully defined and used by physicists to describe motion. Kinematics is the formal method of describing motion.

Obviously, a more formal way of describing motion is necessary to eliminate this type of descriptive ambiguity. Chances are that the descriptions will not be in perfect agreement, even though both observers described the same motion. The need for a formal language is evidenced by a simple experiment: drop an object from about shoulder height and ask two people to independently describe the motion of the object. Kinematics is the formal language physicists use to describe motion.

Describe each motion graph physics