E=mass of earth
M=mass of moon
D=distance between centres of earth and moon.
r=distance from centre of the earth
m=mass of a certain object of the experiment
Using Newton's law of gravitation,
F=GMm/r^2
G=gravitational constant
then
force due to earth
Fe=GEm/r^2
force due to moon
Fm=GMm/(D-r)^2
When they are equal, we have Fe=FM
So
equate Fe=Fm and solve for r in terms of M, E, and D.
The gravitational forces of the Earth and the Moon are attractive, so there must be a point on a line joining their centers where the gravitational forces on an object cancel.
How far is this distance from the Earth's center?
1 answer
1 answer