This means that when
Rationalised 2023-24
38
Physics
bodies are charged through friction, there is a transfer of electric charge
from one body to another, but no creation or destruction
of charge 5 Coulomb’s Law: The mutual electrostatic force between two point
charges q1 and q2 is proportional to the product q1q2 and inversely
proportional to the square of the distance r21 separating them Mathematically,
F21 = force on q2 due to  
1
2
1
21
2
21
ˆ
k
(q q )
q
r
=
r
where 
ˆr21
 is a unit vector in the direction from q1 to q2 and k =  
0
1
4 ε
π
is the constant of proportionality