How many protons are present in an atom which has an atomic number of 47?
Answer in units of protons.

Explanation:

The atomic number of an atom represents the number of protons in its nucleus. Therefore, 47 means that there are 47 protons in the atom's nucleus. In this case the atom is that of silver (Ag).

55 N

Explanation:

Assuming no potential energy changes.

The work applied increases the kinetic energy.

Fd = ½mv²

F = mv²/2d = 0.145(39²) / (2(2.0)) = 55.13625 ≈ 55 N