In a distance-time graph, the gradient of the line is equal to the speed of the object. The greater the gradient (and the steeper the line) the faster the object is moving.
One of the most basic things students do in a physics lab is to collect data and use that to build a model. Most of these models come in the form of a mathematical function. But here is the problem.
A horizontal line means the object is moving at a constant speed. The gradient of the line = the rate of change of speed. The steeper the line, the greater the increase in speed. The area under the ...