Answer:
200 N
Explanation:
F = G m1 m2 / r^2 G m1 and m2 are constant for this scenario
so this becomes
F is proprtional to 1/r^2
f = 1/r^2
800 = 1/r^2 now change r to 2r
F = 1/(2r)^2 = 1/4 * 1/r^2 <======shows force will be 1/4 of original , or 200N