Question

two point charges exert an attractive force of 5.0 N on each other. How much force would they exert on each other if the distance between them were:

a) ten times as great

b) one-tenth as great

c) how would your answers to a and b be altered if at all if the forces the charges exert on each other were repulsive rather than attractive?

(please include all steps/formulas used)

Answer 1

The force between 2 charges is given by KQ1Q2/r^2

K=coulumb constant

Q1&Q2 are magnitude of charges

r=separation between them

Clearly force is proportional to 1/r^2

so if distance becomes 10 times force becomes 1/100 i.e .05N

so if distance becomes 1/10 times force becomes 100 times i.e 500N

The magnitude of force remains the same only the nature of force changes

(Like charges repel each other unlike charges attract each other)