Aswimming pool is 1.4 m deep and 12 m long. is it possible for you to dive to the very bottom of the pool so people standing on the deck at the end of the pool do not see you?
part a assume you dive to the very bottom of the pool so people standing on the deck at the end of the pool can see you. find the minimum height of the person's eyes at the far side of the pool, so you would be observable by this person. take an angle 48.5∘ for a ray that is incident at the water-air interface (nwater = 1.33). express your answer to two significant figures and include the appropriate units.
part b therefore, is it possible for you to dive to the very bottom of the pool so people standing on the deck at the end of the pool do not see you?
therefore, is it possible for you to dive to the very bottom of the pool so people standing on the deck at the end of the pool do not see you?

answer; /// the above statement is (true);

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.