Idea 4of 11Builds onHow fast the speed changesThe walk as a line
Steady change, straight line
Why is the cart's line straight?
Today you'll discover
- two carts: same start and end, only one steady
- why a steady change draws a straight line
- that slowing steadily counts too
Think firstAnother cart: 2 to 6 m/s, in 4 s
This cart also went from 2 to 6 m/s in 4 s. Was its change steady?
Decide first, then press Next. Compare how the two lines get from 2 to 6.
A velocity–time graph on which a flat line at 2 jumps to a flat line at 6 at two seconds. Pressing Next switches to the steady cart, one straight line climbing from 2 to 6 metres per second over four seconds, then shades the slope triangle under it. The last step shows a tram's line falling steadily from 10 to 4 and asks whether its acceleration is uniform.
See the whole ideathe big idea and the key word, in one place
The big idea
Same change every second: a straight line. Uniform acceleration.
See the patternA straight line on a velocity–time graph is a constant acceleration. Its slope is the acceleration, the way a position–time slope is the velocity.
Key word
- uniform acceleration
- an acceleration that does not change: the velocity changes by the same amount in every second
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?
- Tell a steady change from a sudden one on a graph.