Question 419726
a) Write the variation equation
g = {{{(km)/d^2}}}
Where
g = force of gravity
k = constant of variation
m = mass, (the more mass the more gravitational force between them)
d = distance (the more distance, the less the gravitational force between them)
:
b) If the force of gravity between a 105 kg. man and his 80 kg wife when they are separated by a distance of 5 meters is 2.24112X10^-8 (the -8 is an exponent)newtons, find the variation constant.

{{{(105*80*k)/5^2}}} =  2.24112(10^-8); (we use the product of the masses)
{{{(8400k)/25}}} =  2.24112(10^-8) 
336k = 2.24112(10^-8) 
k = {{{(2.24112(10^-8))/336}}}
k = 6.67*(10^-11) Newtons, this is the gravitational constant (G) 
:
c) Find the force of gravity between the man and his wife when they are 2 meters apart.
g = {{{(105*80*6.67(10^-11))/2^2}}} 
g = {{{5.6028(10^-7)/4}}}
g = 1.4007(10^-7) Newtons