Meters/seconds squared
The slope of a force vs. time graph is equal to the change in momentum or the Impulse.
magnitude of velocity
The slope of the speed/time graph is the magnitude (size) of the object's acceleration.
A change in the slope of a location-time graph of an object indicates a change in the radial component of its speed.
The slope of a speed vs time graph indicates an objects acceleration.
On a distance/time graph, the slope of the line is the speed. (Magnitude of velocity.)
slope of the graph ... actually the absolute value of the slope, actual slope, positive or negative, would indicate direction, so the slope would be velocity.
it indicates the acceleration of the particle
A changing slope on a velocity-time graph indicates that the object's acceleration is changing. If the slope is increasing, the acceleration is positive, and if the slope is decreasing, the acceleration is negative. A flat slope indicates constant velocity.
instantaneous velocity
Yes, a position-time graph can have a negative slope. This would indicate that the object is moving in the negative direction with respect to the chosen reference point.
The slope of the speed/time graph is the magnitude (size) of the object's acceleration.