Idea 3of 6Builds onCurved means changing
Same motion, two graphs
How do the two graphs match up?
Today you'll discover
- what a flat piece means on each graph
- how one motion looks on both
- the mix-up to avoid
Think firstA velocity–time line sits flat at 2 m/s
A flat velocity–time line at 2 m/s. What is the object doing?
Answer first, then press Next. Watch the same motion drawn on each graph.
A velocity–time graph with a flat piece at 2 metres per second. After a prediction, the same motion is shown as a straight climb on a position–time graph, then a stop appears on both graphs, then the rule is named. The last step shows a rising velocity–time line and asks what the position graph looks like.
See the whole ideathe big idea and the key word, in one place
The big idea
Flat on d–t: still. Flat on v–t: steady. Check the axis.
Easy to get wrongThe commonest graph mistake is reading a velocity–time line as if it were a position–time line. Look at the axis label before anything else.
Key word
- motion graph
- any graph of a motion against time; a position–time graph and a velocity–time graph are the two this course reads
About this modelBelow the line means moving the other way, not slowing down.
Below the line means moving the other way, not slowing down.
Ready to use it?
- Match a position–time graph to its velocity–time graph.