When the nanocrystalline semiconductor samples provided in case study are irradiated with violet light, you should observe that different samples emit different colors of light. Explain how the trend in the observed emitted colors (from violet towards red) is related to a trend in the band gap energies of these samples.

Due to the different lattice arrangement of nanocrystalline semiconductors, they will be able to emit different colors of light.

Explanation:

An essential feature in nanocrystalline semiconductor samples is that they may not have the same or in some cases similar structures. This characteristic is due to the fact that nanocrystals do not grow equally, presenting different shapes. Nanocrystals with uneven shapes may absorb light of a certain wavelength, but due to their uneven characteristics, the light emitted may be of a different wavelength.

lol

explanation:

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.