In an experiment to measure the quantum yield of a photochemical reaction, the absorbing substance was exposed to 490nm light from a 100w source for 45 min. the intensity of the transmitted light was 40% of the intensity of the incident light. as a result of irradiation, 0.344 mol of the absorbing substance decomposed. determine the quantum yield. (hint (1) calculate the total energy delivered to the source, (2) calculate the energy delivered by 490nm radiation per photon, (3) then calculate the number of photons, (4) then calculate the number of photons absorbed in mol and finally (5) you can calculate the quantum yield. the quantum yield is:
a) .89
b) .67
c) .52
d) .42

answer: electrons

we need to know the time interval during which the force acts. impulse of force = momentum change

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.