Review conceptual example 8 as background for this problem. a loudspeaker is generating sound in a room. at a certain point, the sound waves coming directly from the speaker (without reflecting from the walls) create an intensity level of 75.0 db. the waves reflected from the walls create, by themselves, an intensity level of 72.0 db at the same point. what is the total intensity level?

Level = 76.8 dB

Explanation:

Level of sound intensity is related to the intensity of sound by the following formula

so from above formula we can find the intensity of sound for 75 dB

now for another sound level of 72.0 dB we have

so we have

now the total intensity due to both sounds

Now the level of resultant sound is

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.