An ideal reheat rankine cycle with water as the working fluid operates the inlet of the high-pressure turbine at 8000 kpa and 450°c, the inlet of the low-pressure turbine at 500 kpa and 500°c, and the condenser at 10 kpa. determine the mass flow rate through the boiler needed for this system to produce a net 5000 kw of power and the thermal efficiency of the cycle.

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.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray