Calculate the final speed and distance for a skydiver who waits only 4 seconds to open his parachute.

We don't know . . .

-- the speed of the airplane at the moment he jumped

-- the altitude of the airplane at the moment he jumped

-- the speed or direction of the winds at every altitude all the way down

-- the position he was in during the 4 seconds of "free"-fall

-- the skydiver's weight

-- the drag of his parashoot

Otherwise, this sounds like a fun problem to work on.

I can tell you this:  

The vertical component of the skydiver's total fall is equal to

(the airplane's elevation above sea level at the moment he jumps)

minus

(the elevation above sea level of the ground upon which he lands).

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.