One dimensional motion is when an object moves along a straight line path. The object may move forward or backward along this path.
Constant Velocity
Having a constant velocity means that your speed and direction are not changing. You may be standing still or you may be moving away from or towards the origin at a constant rate.
Position vs. Time Graphs
This object is moving at a constant unchanging velocity. Notice that the position of the object for each 5 second interval is 10 m. The slope is constant for this object (the slope is straight (unchanging) and positive (up). This object is moving away from the origin at a constant velocity.
Velocity vs. Time Graphs
Because the velocity is constant and not changing the slope for this graph is zero. The velocity is the same at each point in time. A constant slope on a distance vs. time graph translates to a zero slope on a velocity vs. time graph
Acceleration vs. Time Graphs
.Notice on the velocity vs. time graph that the slope is zero. This means that the object is not accelerating. The acceleration vs. time graph has a slope of zero
Constant Acceleration
When an object has a constant acceleration, the objects speed will change by the same amount for each time interval. The object may move towards or away from the origin,
Position vs. Time Graphs
Notice how with this graph, the distance covered by the object is changing for each time interval. The slope of this graph is changing (not constant). The object