For the following sections assume concrete of compressive strength of 6,000 psi and reinforcing steel bars with yield strength of 60 ksi to calculate a. the moment of inertia of the uncracked transformed section b. the cracking moment c. the stresses in the steel and concrete right after cracking d. the stresses in the steel and concrete when the moment is 40% of the cracking moment e. the stresses in the steel and concrete when the moment is 140% of the cracking moment f. would the cracking moment be the same for positive and negative moments? justify your answer for each beam.

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.