1) At first, the acceleration opposes the direction of velocity and the object must be slowing down.
2) At t=4, is the object’s velocity would have been at rest if the acceleration changed to 1.5 m/s^2 as the acceleration would now be in the direction of velocity and would work to increase velocity.
3) But here, the acceleration at t=4 abruptly changes to 2 not 1.5 so the velocity doesn’t have to be zero.
4) The velocity at t=7 would be the same velocity as was at t=0.
Is my interpretation of this graph correct? Is there anything else that can be determined about the nature of motion from the graph?
Edit: Point 2 is inaccurate, I think.