The electrostatic force between two charges is given by Coulomb's law:

where
ke is the Coulomb's constant
q1 is the first charge
q2 is the second charge
r is the separation between the two charges
By substituting the data of the problem into the equation, we can find the magnitude of the force between the two charges:
Answer:
Y = 3.87 x 10⁻³ m = 3.87 mm
Explanation:
This problem can be solved by using Young's double-slit experiment formula:

where,
Y = fringe spacing = ?
L = slit to screen distance = 2 m
λ = wavelength of light = 580 nm = 5.8 x 10⁻⁷ m
d = slit width = 0.3 mm = 3 x 10⁻⁴ m
Therefore,

<u>Y = 3.87 x 10⁻³ m = 3.87 mm</u>
Answer:

Explanation:
Position of charge 3q is x = 0
position of charge -2q is x = a
so here we know that
when two charges are of opposite nature then the electric field will be zero on the line joining the two charges at the position near to smaller magnitude charge
So here the electric field will be zero if the field due to 3q is counterbalanced by field due to -2q
so here we can say





so we will have

so the x coordinate of this position is given as

Is this a chemistry question ?