If two negatively charged small sphere, one with twice the charge of the other, are 18cm a part in air. Calculate the charge on each if the force exerted by each on the other is 0.00081?

q₂ = 3.81 x 10⁻⁸ C = 38.1 nC

q₁ = 7.63 x 10⁻⁸ C = 76.3 nC

Explanation:

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

F = kq₁q₂/r²

where,

F = Force = 0.00081 N

k = Coulomb's Constant = 9 x 10⁹ Nm²/C²

q₁ = magnitude of 1st charge

q₂ = magnitude of second charge

r = distance between charges = 18 cm = 0.18 m

Therefore,

0.00081 N = (9 x 10⁹ Nm²/C²)q₁q₂/(0.18 m)²

q₁q₂ = (0.00081 N)(0.18 m)²/(9 x 10⁹ Nm²/C²)

q₁q₂ = 2.916 x 10⁻¹⁵ C²

q₁ = 2.916 x 10⁻¹⁵ C²/q₂   equation (1)

It is given that:

q₁ = 2q₂   equation (2)

Comparing equation (1) and equation (2):

2q₂ = 2.916 x 10⁻¹⁵ C²/q₂

q₂² = 2.916 x 10⁻¹⁵ C²/2

q₂ = √14.58 x 10⁻¹⁶ C²

q₂ = 3.81 x 10⁻⁸ C = 38.1 nC

using this value in equation (2):

q₁= 2(3.81 x 10⁻⁸ C)

q₁ = 7.63 x 10⁻⁸ C = 76.3 nC

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

true is the correct answer

hope i