Its a video of a glider pushed forward and going back
due to a fan blowing of the opposite direction of being
pushed.
After watching this video, Blake, a student in an introductory
physics class, makes the following claim:
The acceleration and velocity of the glider are both
momentarily zero when the glider changes direction. The velocity of
the glider must be zero for an instant when the glider changes
direction. Because the velocity is zero, the acceleration must also...