Which of the following situations does NOT adhere to the law of conservation of energy?

O A metal cord carrying electrical energy transforms that energy into heat energy.

O A book dropped from a person's hand has the same amount of potential energy in the person's hand as it does on the ground.

O A ball rolled up a hill has the same amount of total energy at the bottom of the hill as it does
when it gets to the top of the hill.

O A chemical is burned, and its energy is not lost but instead released into another form.

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.

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000

inverse v=i*r

nice nice