Answer:
F = 3.86 x 10⁻⁶ N
Explanation:
First, we will find the distance between the two particles:

where,
r = distance between the particles = ?
(x₁, y₁, z₁) = (2, 5, 1)
(x₂, y₂, z₂) = (3, 2, 3)
Therefore,

Now, we will calculate the magnitude of the force between the charges by using Coulomb's Law:

where,
F = magnitude of force = ?
k = Coulomb's Constant = 9 x 10⁹ Nm²/C²
q₁ = magnitude of first charge = 2 x 10⁻⁸ C
q₂ = magnitude of second charge = 3 x 10⁻⁷ C
r = distance between the charges = 3.741 m
Therefore,

<u>F = 3.86 x 10⁻⁶ N</u>
E, 63% of the value. I forget the rationale behind it but I learnt that in engineering. 90% confident for that answer.
Answer:
The relative speed of 1 relative to 2 is 0.88c
Explanation:
In relativistic mechanics the relative speed between 2 objects moving in different direction is given by

Since it is given that

Applying values in the formula we get

Answer:
gravitational force
electrostatic force
Explanation:
The forces that balloons may exert on each other can be gravitational pull due to the mass of the balloon membrane and the mass of the gas contained in each. This force is inversely proportional to the square of the radial distance between their center of masses.
The Mutual force of gravitational pull that they exert on each other can be given as:

where:
gravitational constant 
are the masses of individual balloons
the radial distance between the center of masses of the balloons.
But when there are charges on the balloons, the electrostatic force comes into act which is governed by Coulomb's law.
Given as:

where:

are the charges on the individual balloons
R = radial distance between the charges.