Question 858964
The repulsive force f between the north poles of two magnets is inversely proportional to the square of the distance d between them.
 If the repulsive force is 21 lb when the distance is 15 in., find the repulsive force when the distance is 5 in.
:

f = {{{k/d^2}}}
find k, f=21; d=15
{{{k/15^2}}} = 21
k = 21*225
k = 4725
Find f when d=5
f = {{{4725/5^2}}}
f = 189 lb