1) coffee is always under constant acceleration (g).
2) constant acceleration (say in the X direction instead of Y) would just mean a constant "tilt" within the cup. compare this to an airplane that is not "accelerating" and just at a constant X velocity, coffee would look "still/flat" in your cup.
3) its only the jerk that changes the "tilt" within the cup (and hence causes the spill)
1) coffee is always under constant acceleration (g).
2) constant acceleration (say in the X direction instead of Y) would just mean a constant "tilt" within the cup. compare this to an airplane that is not "accelerating" and just at a constant X velocity, coffee would look "still/flat" in your cup.
3) its only the jerk that changes the "tilt" within the cup (and hence causes the spill)