Two identical spheres have a negative charge q and are separated by a centre-centre distance r.Describe the effect the following changes will have on the electric foce F exerted by each sphere:

(a) the distance between the two spheres decrease to 1/2 r.
(b) the charge on each sphere becomes 2q. Two identical spheres have a negative charge q and are separated by a centre-centre distance r.Describe the effect the following changes will have on the electric foce F exerted by each sphere:

(a) the distance between the two spheres decrease to 1/2 r.
(b) the charge on each sphere becomes 2q. @Physics

Question

Two identical spheres have a negative charge q and are separated by a centre-centre distance r.Describe the effect the following changes will have on the electric foce F exerted by each sphere:

(a) the distance between the two spheres decrease to 1/2 r.
(b) the charge on each sphere becomes 2q. Two identical spheres have a negative charge q and are separated by a centre-centre distance r.Describe the effect the following changes will have on the electric foce F exerted by each sphere:

(a) the distance between the two spheres decrease to 1/2 r.
(b) the charge on each sphere becomes 2q. @Physics

anonymous · Answer

Since $$F _{12}=k_{e}(q_{1}q_{2})/r^2$$ if you decrease the separation by half, $$1/r^2$$ becomes a multiplier of 4 regarding the force.
Same as if both q's become 2q. A multiple of 4.