Question

Two point charges each of $1C$ separated by $1m$ distance experience a force of $5.6\times {10}^{9}N$ in vacuum. How much force is experienced by them if they are immersed in water., keeping the distance of separation between them same?
$K=80$ for water.

Answer 1

Force experienced $=5.6\times {10}^{4}N$

when system placed in water, $k=80$

then force $=\frac{5.6\times {10}^9}{80}$

$=7\times {10}^{9}N$

Hence, the answer is $7\times {10}^{9}N.$