The physics of a object are the same whether it moves along the direction of the x-axis or the y-axis. To model this, take a position graph as shown below. The initial position of the object at time ti is si and its final position . To find the velocity of the object, you must find the rise/run of the line. By rearranging the above equation, we arrive at one of the fundamental equations of kinematics for motion in one dimension: Uniform motion is a very simplified version of the motion that happens in the real world. Rarely will you find an object moving at a constant velocity for long periods of time. As seen from previous position graphs, when velocity increases the slope of the line also increases, causing an upwards curving graph. Instantaneous velocity is derived using concepts from calculus. Stated in terms of limits, this looks like.
