The earth is four times the size of the moon and the acceleration due to gravity on the earth is 80 times that on the moon. The ratio of the mass of the moon to that of the earth is
1:80
1:320
1:1280
1:4
Explanation
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Discussions (38)
If you use G=(gr^2)/m you will get 1:1280
G=ge×re^2/Me
G=gm×rm^2/Mm
ge×re^2/Me=ge×re^2/Mm
ge=80gm
The size of the earth is 4 times the size of the moon meaning that
re=4rm
80gm×(4rm)^2/Me=gm×rm^2/Mm
divide both sides by gm×rm^2
80×4^2/Me=1/Mm
1280/Me=1/Mm
cross multiply
Mm/Me=1/1280
Re = 4Rm
ge = 80gm
F = GMm/R²
F=mg
g =GM/R²
G = gR²/M
Ge = Gm
gR² gR²
------ = -------
M M
80gm× (4Rm)² = gmRm²
----------------------- ------------
mE mm
Me gm(Rm)²
------ = -----------------
Mm 80gm× (4Rm)².
Me 1
------ = -----
Mm 80×16
Me 1
------ = -----
Mm 1280
Me:Mm = 1:1280
C is correct
corrections should be made @myschool.ng
My school nawa for una self the correct answer is 1/1280. which C
g =Gm/d²
G =gd²/m
g1d1/m1 =g2d2/m2
Mm/Me= gmdm²/gede²
Mm/Me =1*1/80*16
Mm/Me =1/1280 
thanks everyone it actually a total blunder,
it is very wrong
when they mean size they where talking about
radius R and R must be squared which means
4x4
