Explain, in a sentence, whether the gravitational force between the nuclei is attractive or repulsive.?

Question

And calculate it's strength in newtons.

Two nuclei of nitrogen-14 each have masses of 2.3 × 10−26 kg and are separated by a distance of 2.0 m. The electric charge of each nucleus is +7e.

Express your answer in scientific notation to two significant figures.

Answer 1

Gravitational force is always attractive, dude!!

You must be speaking of Electrostatic force, I guess...

1. F(g) = GMm/r^2 = 6.67  .  10^-11  .  (2.3  .  10^-26)^2 / 4 = of the order of 10^-63 => meaningless(negligible).

2. F(e) = KQq/r^2 = 9  .  10^9  .  (7  .  1.6  .  10^-19)^2 / 4 = 2.82  .  10^-36 N

[. vastly separated above => multiplication]

Here F(e) >> F(g).

So the net force between the nuclei is electrostatic repulsive because both have same charge.

Net force = F(e)[repulsive] - F(g)[attractive] = F(e) approx. = 2.8  .  10^-36 N.