It means the velocity is constant.
Motion at constant speed.
Acceleration
The slope of [distance vs. time] is [speed]. If the slope is constant, then the speed is constant,meaning the magnitude of acceleration is zero.(The direction of velocity might still be changing though, which wouldn't show up on the graph.)
the slope at any point on the graph is the acceleration
The slope of a velocity-time graph represents acceleration.
The slope of a position/time graph is the speed (magnitude of velocity).If the graph's slope is changing, that means the speed is changing, andthat would be accelerated motion.
The motion at constant speed.
Motion at constant speed.
It means that the velocity is constant, or not changing.
Assuming the graph is for displacement versus time, the motion should be constant velocity. If velocity versus time motion is constant acceleration
"Slope" is the steepness of the line on any graph.
distance = velocity x time so on the graph velocity is slope. If slope is zero (horizontal line) there is no motion
That slope is the 'speed' of the motion. If the slope is changing, then the speed is changing. That's 'accelerated' motion. (It doesn't matter whether the speed is growing or shrinking. It's still 'accelerated' motion. 'Acceleration' does NOT mean 'speeding up'.)
Steep slope on a distance/time graph indicates high speed.
flat
The rate of acceleration.
The motion at constant speed.