Force (F) varies inversely with the square of its distance (r2). When 2 objects are 0.33 meters apart, force is 9.6 Newtons. How much force (F) if distance (r) is 0.75 meters?

Answer 1

Varies inversely means a y=k/x situation. So for your problem, we could say F=k/r² 

 

F=k/r² (definition of inverse relationship)

9.6 = k/(.33)² (plugging in your given information)

k = 9.6(.33)^2 = 1.04544

 

Now you have an equation good for ANY distance/force relationship:

 

F = 1.04544/r²

 

Now you can plug in the new information, and solve for your unknown:

 

F(0.75) = 1.04544/(.75)² = 1.858488.....

 

Rounded to the nearest thousandth would be 1.8585 Newtons