Answer:
potential energy increases.
Explanation:
The potential energy between the two charged particles is given by
U = k Q q / r
If they are very far apart then r tends to infinity and the potential energy is zero.
If they come closer then the potential energy between the two charged particles increases.
Thus, the potential energy increases.
The box is accelerated from rest to 4 m/s in a matter of 2.5 s, so its acceleration <em>a</em> is such that
4 m/s = <em>a</em> (2.5 s) → <em>a</em> = (4 m/s) / (2.5 s) = 1.6 m/s²
Then the force applied to the box has a magnitude <em>F</em> such that
<em>F</em> = (10 kg) (1.6 m/s²) = 16 N