Ared laser pointer shines on a diffraction grating, producing a diffraction pattern on a screen behind the grating. if the red laser pointer is replaced with a green laser pointer, will the green bright spots on the screen be closer together or farther apart than the red bright spots were?

Closer together

Explanation:

A red laser pointer shines on a diffraction grating, producing a diffraction pattern on the screen behind the grating. In diffraction grating the width of the the diffraction pattern is proportional to the wavelength of light used. Since the wavelength of green light is smaller than red therefore, the width of the pattern is smaller. Hence the green light spots will appear closer.

i guess it’s a and b

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.