A cart moving along a straight track has its position x measured at several instants, as recorded in the table below (positive x is east).
Time t (s): 0 2 4 6
Position x (m): 0 +4 +1 −3
Use the data to answer the questions that follow. Show all work, include units, and clearly indicate the sign of any vector quantity.
(a) Determine the cart’s displacement between t=0s and t=6s.
(b) Calculate the cart’s average velocity over the same time interval.
(c) Calculate the cart’s average speed over the same time interval.
(d) Explain why the average speed you found in part (c) differs from the magnitude of the average velocity in part (b). Relate your explanation to the motion described by the position data.