En pocas palabras la utilidad que le darias al hecho de conocer los principios y leyes que rigen el movimiento de los cuerpos

we can predict where they are in the future, know where they were in the past

can also build a device that generates a specific type of desired movement,

Explanation:

With the knowledge of the laws that govern the movement of bodies, we can predict where they are in the future and therefore know if there may be an accident, crash.

We can also know where they were in the past and therefore know if a fact is the result of these movements, craters, collapse of buildings, etc.

We can also build a device that generates a specific type of desired movement, for example pulleys that help us with work, etc.

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

pe = weightxheight = 2000x1000=2,000,000joules