To develop this problem, it is necessary to apply the concepts related to the Gravitational Force and its respective change related to the black hole.
Gravitational Force are given as

Where
l = Length
R = Separation between both
M = Mass of Object
m = mass of block hole
G = Gravitational Universal constant
Our values are given as
l = 100m
M = 1490
is mass of sun
R = 10km
PART A ) Replacing in our equation we have that



PART B) The difference at this force would be given as

As Force is equal to mass and gravity then



