Learn the difference between distance, displacement, speed and velocity, and how to calculate distance, speed and acceleration.

But if you calculate the acceleration without the graph, you are explicitly stating that the y-intercept is zero---which it might not be. So there are some actual reasons for making a graph.

Find the acceleration of the sledge when t = 6 s. Draw a tangent to the curve at the point where t = 6s and draw two lines to form a right angle triangle.