The answer will depend on whether the graph is a distance time graph or a speed time graph.
The slope of a distance-time graph shows that speed of the object in the direction towards or away from the point of reference (usually the origin). It indicates absolutely nothing about its speed in any other direction. So, for example, an object could be rotating around the origin at the speed of light (the fastest possible) and the distance-time graph would show it being stationary bacause its distance from the origin is not changing!
The slope of the speed-time graph indicated the acceleration of the object, again with the same qualification.
The slope of a speed vs time graph indicates an objects acceleration.
instantaneous velocity
It is a measure of speed of the object, but only in the radial direction: that is, towards or away from the point from which distance is measured. The object could be going around that point in circular motion and the graph would show absolutely nothing.
magnitude of velocity
The rate of acceleration.
The slope of the speed/time graph is the magnitude (size) of the object's acceleration.
The slope of a speed vs time graph indicates an objects acceleration.
A change in the slope of a location-time graph of an object indicates a change in the radial component of its speed.
instantaneous velocity
It shows the component of velocity in a radial direction. Any motion in a transverse direction is ignored.
It is a measure of speed of the object, but only in the radial direction: that is, towards or away from the point from which distance is measured. The object could be going around that point in circular motion and the graph would show absolutely nothing.
The slope of the speed/time graph is the magnitude (size) of the object's 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
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.
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'.)
The slope of a force vs. time graph is equal to the change in momentum or the Impulse.