Question

help??

Two charged spheres are 20.0 cm apart. They are moved, and the force on each of them is found to have been quadrupled. How far apart are they now?

Answer 1

For this question i think we have to make some assumptions and conversions
1. The spheres are identical and charge on them is same.
2. No other force is acting on system (only electrostatic force is acting).
3. Convert all quantities in same system of units (S.I units)

Now, we know according to coulombs law. \[F=\frac{ KQ ^{2} }{ r ^{2} } \]
So, CASE 1
\[F=\frac{ KQ ^{2} }{ 0.2^{2} }\]
CASE 2
\[4F=\frac{ KQ ^{2} }{X ^{2} }\]
where X is the final separation between spheres
Comparing both cases we get
\[X ^{2}=\frac{ 1 }{ 100 }\]
SO, X=0.1 m
OR
10 cm

Answer 2

Thank you so much!