A soccer ball would keep moving forever without physics, because without force to act upon the soccer ball, it could, or will not be able to stop the acceleration. And force is a factor in physics.
Answer:

Explanation:
At some distance from the Earth the force of attraction due to moon is balanced by the force due to Moon
so we will have

now we have


so we will have

Now by energy conservation



It takes twice the force to produce the same acceleration in the 2kg rock.
Answer:
The man's total displacement is equal to 0.
Explanation:
Given that,
A man ran a 5 mile race. The race looped around a city park and back to the starting line.
We need to find the total displacement of the man.
We know that,
Displacement = shortest path covered
Also,
Displacement = final position - initial position
As it reaches back to its starting line, it means, the displacement is equal to 0.
Hence, the man's total displacement is equal to 0.