Worked example
A cart travels from 1 m to 7 m and back to 3 m along a track. Its distance is 6 + 4 = 10 m. Its displacement is 3 − 1 = +2 m. A position–time graph would slope upward on the outward leg and downward during the return.
Contrast and common error
A cart can move right while accelerating left: a leftward net force changes its rightward velocity toward zero. If the net force is zero, its velocity stays constant. It would remain at rest only if it started at rest.
Transfer check
A 4 kg cart moving left feels 7 N to the right and 3 N to the left. Find its initial acceleration and describe its speed immediately after the forces act. Check: net force is 4 N right, so acceleration is 1 m/s² right. While it is still moving left, it slows.
Try it, then explain it.
Complete a short set without looking at the example. After each answer, explain which evidence or rule supports your decision and why the alternatives do not fit.
Sources & authorship
Original OpenExam explanations and examples. References support the concepts; they are not the source of copied questions. Independent educator review is pending.
OpenStax Physics 4.3 Newton's Second LawOpenStax Physics 2.1 Relative Motion Distance and Displacement