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.

Velocity-time graphs show how the velocity (or speed) of a moving object changes with time. These graphs also show if the object is moving at a constant speed or accelerating, decelerating, or still.

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 ...