Working displayed in the picture below, the answer is -11 m s^-2
Answer:
In a two particle system, the center of mass lies on the center of the line joining the two particles.
Answer: I looked it up and it says something about the waves traveling in a solid but I don’t know if that’s correct.
The work done to pull the sled up to the hill is given by

where
F is the intensity of the force
d is the distance where the force is applied.
In our problem, the work done is

and the distance through which the force is applied is

, so we can calculate the average force by re-arranging the previous equation and by using these data:
CORRECT ANSWER:
d. Anywhere from days to thousands of years.
STEP-BY-STEP EXPLANATION:
The whole question from book is
How long do molecules of groundwater stay in the
ground?
a. Days
b. Weeks
c. Months
d. Anywhere from days to thousands of years