Tại một đập thủy điện, mực nước ngọt ở phía sau đập có chiều cao h = 15m so với miệng cống xả nước (dùng để xả nước ra phía trước đập khi mực nước quá cao, được đậy bằng một nắp cống ngăn nước ra ngoài). Tiết diện nắp ống xả thải bằng 30cm2 khối lượng riêng nước là 1000kg/m3, tính áp lực tác dụng lên nắp do chênh lệch áp suất giữa bên trong và bên ngoài đập nước?

layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .

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.