Motion

Topics in this chapter

1. 1Motion: Chapter IntroductionSitting still? With the Earth you are moving at about 1,500 km/h. Motion is a change of position with time, measured from a reference point, and this chapter gives the tools to describe it. Watch
2. 2Rest and Motion: Motion is RelativeAre you moving right now? It depends on who is watching. Rest and motion are always measured from a reference point. Watch
3. 3Position Needs an Origin and a Direction"200 m" means nothing until you say from where and which way. Position is a signed number with a unit, measured from a chosen origin. Watch
4. 4Distance vs DisplacementDistance counts the whole path you walked; displacement only looks at the straight line from start to end, with its direction. Watch
5. 5Speed vs VelocityTwo cars at the same 60 km/h can have different velocities. Speed tells how fast; velocity also tells which way. Watch
6. 6Average Speed vs Average VelocityWalk 4 km to school and back in an hour: average speed 4 km/h, average velocity zero. One uses total distance, the other displacement. Watch
7. 7Uniform and non-uniform motionComing soon
8. 8Acceleration: what it really meansComing soon
9. 9Positive, negative and zero accelerationComing soon
10. 10Retardation or decelerationComing soon
11. 11Distance–time graph: reading motionComing soon
12. 12Velocity–time graph: reading motionComing soon
13. 13Slope of a distance–time graphComing soon
14. 14Slope of a velocity–time graphComing soon
15. 15Area under a velocity–time graphComing soon
16. 16How to interpret a flat, rising or falling graphComing soon
17. 17Instantaneous speed (intuitive introduction)Coming soon
18. 18Scalar and vector quantitiesComing soon
19. 19SI units of distance, speed, velocity and accelerationComing soon
20. 20Why a round trip can have zero displacement but non-zero distanceComing soon