You and your little cousin sit on a see-saw. You sit 0.5 m from the fulcrum, and your cousin sits 1.5 m from the fulcrum. You weigh 600 N. How much does she weigh?

200N

Explanation:

Distance from fulcrum by you  = 0.5m

Distance from fulcrum by cousin  = 1.5m

Your weight  = 600N

Unknown:

Weight of my cousin = ?

Solution:

From the principle of moment, when an object is balanced, the sum of the clockwise moment is equal to the sum of the anti-clockwise moment.

So;

   Your weight x distance from fulcrum by you  = Weight of cousin x her distance from the fulcrum

   600 x 0.5  = weight of cousin x 1.5m

    Weight of cousin  = 200N

prolly a beacuse the momentuem the car has increases while going down hill

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.