Kinematic Graphing - Mission KG8 Detailed Help

 This velocity-time graph depicts the motion of an object. Use the graph to determine the acceleration (in m/s/s) of the object. If negative, then enter a negative answer.
 Velocity-Time Graphs: Velocity versus time graphs represent changes that occur in an object's velocity with respect to time. The slope of the line is the acceleration (change in velocity divided by the change in time) of the object. The area under the line (between the line on the graph and the time axis) is the displacement of the object.
 The task of determining the slope of the line on a graph involves: Picking two points on the line and determining their x-y coordinates. It is critical to select points whose coordinates are clearly known and not simply guessed at. Based on the coordinates of these two points, determine the amount of rise of the line between the two points. The rise is the change in the y-coordinate for the line as it stretches from the first selected point to the last point. Determine the amount of run of the line between the two points. The run is the change in the x-coordinate for the line as it stretches from the first selected point to the last point. Calculate the ratio of rise to run: slope = rise/run. Check the sign on your slope value to insure its accuracy. A downward sloping line has a negative slope.
 The Minds On Physics program calculates answers accurate to several decimal places. Your answer does not need to be that accurate. The program will allow you to have a deviation of approximately 1% from the right answer without being wrong. This means you should enter your answer to at least the second decimal place.