Consider a spring that does not obey hooke's law very faithfully. one end of the spring is fixed. to keep the spring stretched or compressed an amount x, a force along the x-axis with x-component fx=kx−bx2+cx3 must be applied to the free end. here k=100n/m, b=700n/m2, and c=12,000n/m3. note that x> 0 when the spring is stretched and x< 0 when it is compressed. (a) how much work must be done to stretch this spring by 0.050 m from its unstretched length? (b) how much work must be done to compress this spring by 0.050 m from its unstretched length? (c) how much work must be done to move the spring from being compressed by 0.070 m to being stretched by 0.030 m, assuming the end moves with constant speed during the motion?

insects!

explanation:

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

root word, prefixes, and suffixes

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.