The separation distance between two 1.0 kg masses is changed. how is the mutual gravitational force affected in each case?

First case : Gravitational force = 1.5625

Second case : Gravitational force = 0.04

Explanation:

a) The separation distance is four-fifths the original distance.

  Distance decreases, so force increases.  i .e., F2 ÷ F1

so ( )²

    =

    = 1.5625

b) The separation distance is 5 times the original distance.  i.e. F2 ÷ F1

Distance increases, so force decreases.

so ²

 =

 = 0.04

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .