The object is accelerating
An upward sloping straight line indicates that the object being studied is moving away from the origin and that the component of its velocity in the radial direction is a constant. A downward sloping line indicates it is moving towards the origin. However, neither line says anything about the transverse component of its motion.
The horizontal line represents that the acceleration is zero or constant speed and the line that slopes downward means that the object is slowing down and it is a negative acceleration.
This means your velocity is decreasing with time, or in other words, the object is slowing down.
That the object being studied is accelerating in the radial direction.
On a graph of acceleration vs. time, during deceleration the line is below zero. On a graph of speed vs. time, during deceleration the line has a negative slope (sloping downward from left to right).
Slowing down or decelerating
Deceleration can be symbolized as a negative value in an equation or graph, indicating a decrease in speed or velocity. It can also be represented by a downward sloping line on a velocity-time graph, showing a decrease in velocity over time.
The object is accelerating
An upward sloping straight line indicates that the object being studied is moving away from the origin and that the component of its velocity in the radial direction is a constant. A downward sloping line indicates it is moving towards the origin. However, neither line says anything about the transverse component of its motion.
The horizontal line represents that the acceleration is zero or constant speed and the line that slopes downward means that the object is slowing down and it is a negative acceleration.
An downward sloping diagonal line on a position vs. time graph indicates constant negative acceleration or deceleration. This means that the object is moving in the negative direction and slowing down over time.
This means your velocity is decreasing with time, or in other words, the object is slowing down.
That the object being studied is accelerating in the radial direction.
That means the speed (the slope of the position-time graph) is decreasing.
It means that either the distance is measured from the starting-line and the object is moving forward, or else the distance is measured from the finish-line and the object is moving backwards, because the distance is growing as time goes on. If the upward sloping diagonal line is straight, it means the speed is constant. (not velocity)
The velocity versus time graph would be a straight line sloping downward. The velocity would start at 0 when the object is released, then increase linearly in the negative direction as it accelerates due to gravity.