The experimenter from the video rotates on his stool, this time holding his empty hands in his lap. you stand on a desk above him and drop a long, heavy bean bag straight down so that it lands across his lap, in his hands. what happens? hints

The answer would be he will spin slower.  The bean bag is not spinning beforehand it contacts the experimenter, so (through conservation of rotational momentum) he must stock the rotational momentum mandatory to make it spin at the same degree as his lap. Consequently, he ends up spinning slower.

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.