A physics student with a strong interest in analyzing motions spots a dog making a chase in a straight line. The student uses a coordinates system where the motion is parallel to the x-axis and to the right is the +x direction. The student makes measurements of the dog's motion and constructs a graph of velocity as a function of time. Determine the dog's velocity at 2.5 s and 6.0 s.

Examine the graph illustrating the position of a ship navigating a straight river over time. Determine the ship's average velocity during the time interval from t = 25.0 s to t = 50.0 s.

Chloe walks to her school daily which is 300 m from her home. Using her position-time graph find the velocity at t = 500s 

Below is a position-time graph of a subway train traveling from London to Edinburgh. Find the train's velocity at t = 20 s