This graph shows the altitude of a bird over time. What is the slope of the line and what does it mean in this situation? The slope is –500 . This means that the bird descends 500 m each minute. The slope is –350 . This means that the bird descends 350 m each minute. The slope is 350. This means that the bird ascends 350 m each minute. The slope is 500. This means that the bird ascends 500 m each minute.