Physics force between two objects

Question

Two point charges are separated by 3.4 cm . The attractive force between them is 22 N. Find the force between them when they are separated by 8.8 cm .

Answer 1

The force of attraction between two point charges is given by the equation

F = KQ1Q2 / R^2, where K is a constant called coulomb's constant, the Q are the value of the point charges in Coulombs, and R is the separation distance in meters.

The force between them when separated by 3.4 cm (0.034 meters is given as 22N.

Therefore 22 N = KQ1Q2 / 0.034^2. The force when the distance is 8.8 cm (0.088 m) can be written as

F = KQ1Q2 / 0.088^2.

If we take the ratio between the two forces, we get F / 22N = KQ1Q2 / 0.088^2 / KQ1Q2 / 0.034^2.

KQ1Q2 cancels out leaving F / 22N = 0.034^2 / 0.088^2 so F = 0.034^2/ 0.088^2 x 22 N = 3.28 N.

Check math.