Line 1: The spacing is the same. Uniform
Line 2: The spacing is increasing.
Line 3: The spacing is decreasing.
The dots seems to be the one made by a ticker tape timer. A device that used to find the velocity/acceleration of bodies at a short distances.
When you look at the space between the dots in line 1, you will see that the gaps are uniform. The distances between the dots are the same. If the dots were from a ticker time, then it would represent a constant velocity.
The spaces from the left are be coming bigger as you move to the right. That is the spacing is increasing. If it is from a ticker time, these would represent an increasing velocity.
The spaces are decreasing from left to right. That is the distance is becoming smaller. For a ticker timer is could mean a decreasing the velocity.
The dots in line 1 are spaced evenly. The dots in line 2 get farther apart. The dots in line 3 get closer together.
Line 1: the spacing is even the whole time
Line 2: the spacing increases over time
Line 3: the spacing decreases over time
hope this helps!
probably not if net force is zero
graph question answered .. you think better when you are relaxed and happy