Answer:
- The distance between the charges is 5,335.026 m
Explanation:
To obtain the forces between the particles, we can use Coulomb's Law in scalar form, this is, the force between the particles will be:

where k is Coulomb's constant,
and
are the charges and d is the distance between the charges.
Working a little the equation, we can take:


And this equation will give us the distance between the charges. Taking the values of the problem

(the force has a minus sign, as its attractive)




And this is the distance between the charges.
Impulse = Ft = (m)(delta v)
delta v = change in velocity = velocity final - velocity initial.
= -22m/s - +18m/s = -40m/s.
mdeltav = (0.40kg)(-40m/s) = -16kgm/s or -16Ns.
I don't believe their is a legitimate answer for this question..
The answer is A. Reactivity
hope this helps