atomic structure

why do like charges repel and opposite attract?

1
swordfish ·

Because of the difference in electric force experienced by like charges and unlike charges.

1
Vinay Arya ·

I think you might have read electrostatics.
Force between two charges is given by:
F=Kq1q2r2
Consider the case when both are positive
In that case F is positive.
Consider the case when the charges are opposite
In that F is negative.
Please do the calculations also to get it.
Now the two forces are differing in their signs.So it means that they are of opposite nature.
Swordfish is absolutely right.
You might have read in the textbooks that - is shown for attraction.So + should be for repulsion.
I think you have understood.

1
manisha ·

my question is why does force between any two bodies exist?

21
Shubhodip ·

QED (Quantum electrodynamics) suggests that charges interact through virtual (invisible) photons. I don't know the exact explanation of attraction, but repulsion is quite easy. Suppose you are on a boat and your friend is in another boat. If you have a volley ball and you throw it to your friend, then your boat will move backwards. When your friend catches the ball, the momentum of ball will push his boat backward too. On the whole, you are getting away from each other by throwing the ball to each other. All the charges keep emitting these virtual photons, and whenver a like charge comes in vicinity, this ball game starts between them, and they move away from each other.
For attraction, the momentum is in opposite direction (I don't think I am very clear here), so that when virtual photons are exchanged between unlike charges, it results in both of them moving towards each other.

However, it is best to assume for the time being that charge interaction is the natural way in which charges interact.

source : www.physicsforum.com

1
Vinay Arya ·

Does reason of reason exist?
It is the property of the charges that like charges repel each other and unlike charges attract each other.These have been made so.It is their nature.