It is not possible to answer the questions since there is no such thing as a zero axis.
In a velocity-time graph it will be the time axis (where velocity = 0). On a distance-time graph it will be a line parallel to the time axis: distance = some constant (which may be 0).
Constant speed ... zero acceleration.
a horizontal line
when the slope is 0, the graph is a horizontal line on the x axis so the y axis is perpendicular to it, which can be written x=0
That kind of depends on what is being graphed. -- On a graph of acceleration vs time, the graph is a straight line that lays right on top of the x-axis, because the acceleration is a constant zero. -- On a graph of speed vs time, constant speed is a horizontal line, parallel to the x-axis. -- On a graph of distance vs time, constant speed is a straight line with a positive slope; that is, it rises as it progresses toward the right.
In a velocity-time graph it will be the time axis (where velocity = 0). On a distance-time graph it will be a line parallel to the time axis: distance = some constant (which may be 0).
in a graph, a line with a zero slope is the one that is parallel to the x-axis. It is represented by an equation of the form y = a constant, independent of x values.
The y-axis on a graph is the line that runs up and down through zero. The x-axis is the line that runs horizontally through zero. Both lines help people make their measurements in math.
Constant speed ... zero acceleration.
a horizontal line
where the line on a graph intercepts the y axis, also, it is called the zero step.
On a speed versus time graph, acceleration is represented by the line on the graph. If acceleration is constant, the line cuts through equally between the axis and starts from the zero point.
when the slope is 0, the graph is a horizontal line on the x axis so the y axis is perpendicular to it, which can be written x=0
That kind of depends on what is being graphed. -- On a graph of acceleration vs time, the graph is a straight line that lays right on top of the x-axis, because the acceleration is a constant zero. -- On a graph of speed vs time, constant speed is a horizontal line, parallel to the x-axis. -- On a graph of distance vs time, constant speed is a straight line with a positive slope; that is, it rises as it progresses toward the right.
it would be horizontal line slope zero since it is not accelerating
Constant velocity implies zero acceleration, so you would have a horizontal line, identical to the x-axis.
-- If the graph displays speed against time, then speed of zero is indicated wherever the graph-line touches the x-axis. -- If the graph displays distance against time, then speed of zero is indicated wherever the graph-line is horizontal. -- If the graph displays acceleration (magnitude) against time, then the graph can tell you when speed is increasing or decreasing, but it doesn't show what the actual speed is.