Motion Diagrams
A motion diagram represents the motion of an object by displaying its location at various equally spaced times on the same diagram. For simplicity, the object is represented by a simple shape, such as a filled circle. For example, the applet to the right could represent the motion diagram for a car moving from right to left, approaching a stoplight. The car moves with decreasing speed; the acceleration is thus in the opposite direction to the velocity. Click "Go" and watch the object move several times. When you have a clear idea of the motion, click "Show Displacements" to see the displacement vectors of the object from each location to the next. The decreasing spacing of successive images or equivalently, the decreasing lengths of the displacement vectors, indicates that the object is slowing down. You can also observe motion diagrams for objects that are speeding up and moving with constant velocity.