The graph above is for an object which is thrown vertically upwards with an initial velocity of 20 m/s. In the time period 0-2 seconds – the object decelerates from 20 m/s to 0 m/s.

Because the length of each segment is the distance travelled in one second, the heights of the bars form a bar graph of velocity vs. time. During each second the graph shows that the velocity ...

Why do you always make a graph in physics lab? It's not just for fun, there is a reason. Here is an example.