Electrostatic Force And Its Affect On 3D Objects

[siliconProgrammer]

So I am new to this science forum so please have mercy. I just have some basic questions about electrostatic forces. I hope these are not too vague. So basically from my understanding, if you have two oppositely charged particles, the opposites will attract due to the electrostatic force. The strength of force is predicted by Coloumb’s law. My question is can these charged particles also be charged objects? And when they attract and meet, is there a formula for the speed and time that they would take to be joined together? I want to understand the affect of the electrostatic force on objects. So basically if you had two 10 x 10 x 10 micron cubes of matter, each of the opposite charge, what would be the properties of their connection and attraction? I am trying to test out many ideas that I have and I need a firm understanding of electrostatics. I'm sorry if I am vague. Are there any good tutorials and software simulations online?

[exchemist]

So I am new to this science forum so please have mercy. I just have some basic questions about electrostatic forces. I hope these are not too vague. So basically from my understanding, if you have two oppositely charged particles, the opposites will attract due to the electrostatic force. The strength of force is predicted by Coloumb’s law. My question is can these charged particles also be charged objects? And when they attract and meet, is there a formula for the speed and time that they would take to be joined together? I want to understand the affect of the electrostatic force on objects. So basically if you had two 10 x 10 x 10 micron cubes of matter, each of the opposite charge, what would be the properties of their connection and attraction? I am trying to test out many ideas that I have and I need a firm understanding of electrostatics. I'm sorry if I am vague. Are there any good tutorials and software simulations online?

There is certainly a formula for the force of attraction or repulsion between two charges. Once you know the force and the masses of the objects then you can work out what acceleration will result, from Newton's laws. The formula for the force is given here: https://en.wikipedia.org/wiki/Coulomb's_law

 

But one thing you that complicates matters is that as r, the distance between the objects, decreases, the force will increase, according to the formula. So you are going to have to do an integration, to see how the velocity changes, because the acceleration rate will increase. I am not going to attempt this on a Friday night after a glass of wine! But I hope this at least points you in a helpful direction. 

[OceanBreeze]

 Curiosity, as always, got the better of me and I worked out the math. One thing that interests, is the enormous difference between the electrostatic force and the gravitational force; evident just from comparing the magnitude of Coulomb’s constant (8.99 x 10^9) with the gravitational constant (6.67 x 10^-11).

 

If you had two 1 kg spheres at a distance of 1 meter, it would take about 26 hours for gravity to pull them together. If they each had an opposite charge of 1 Coulomb, the electrostatic force would snap them together in about 8 microseconds. Fast, but still about 2,000 times slower than the speed of light.

 

If I did the math right, T in seconds:

 

T = π/4 √(Kq) where K is Coulomb’s constant and q is charge on one sphere in Coulombs

 

T = π/4 √(Gm) where G is gravitational constant and m is mass of one sphere in kilograms

 

The initial distance r, of 1 meter doesn’t show up in the final answer because I use a trig substitution in the integration and r becomes theta and is fully accounted for by π

 

No, I am not going to post the complete solution! :nea: 

 

[OceanBreeze]

Thanks for the "Like" Craig! But I am a bit disappointed nobody has asked for the complete solution! No, no really