A graph titled Position versus time for with horizontal axis time (seconds) and vertical axis position (meters). The line runs in 3 straight segments from 0 seconds 0 meters to 4 seconds 12 meters to 6 seconds 12 meters to 12 seconds 0 meters. Based on the graph, describe what is happening between 4 and 6 seconds. The object is moving away from the start at a constant speed. The object is not moving. The object is returning to the start at a constant speed. The object is changing speed.