Final answer:
These questions are from the subject of Physics and involve understanding the principles of kinematics, including the interpretation of motion graphs like velocity vs. time and position vs. time, and concepts of velocity, acceleration, and displacement.
Step-by-step explanation:
The subject of the questions presented is Physics, specifically related to motion and kinematics. These topics typically involve understanding the relationship between velocity, acceleration, and time as well as interpreting motion graphs.
When examining the velocity vs. time graph for a jet car, determining the acceleration involves finding the slope of the graph. If the graph's slope is constant at 5.0 m/s², then at any point, the acceleration of the car is indeed 5.0 m/s². For a position vs. time graph, the slope at any given point represents the object's velocity. Therefore, if the graph indicates that the velocity of the jet car is 115 m/s at t = 20 s, it will be reflected by the slope of the graph at that specific time. In the case of an object like a train that changes its state of motion, the shape of its position vs. time graph would reflect its acceleration, constant velocity, and deceleration as described. When it comes to displacement, especially during round trips where the starting and ending positions are the same, the displacement is zero because displacement measures the net change in position.