Two planets, Planet 1 and Planet 2, orbit the same star. Planet 1 has a relative mass of 4x and a relative distance of x. Planet 2 has a relative mass of 3x and a relative distance of 2x. Which planet has a higher gravitational attraction to the star?
I think this is Planet 1 because the ratio of mass to distance is greater, which makes the value of F greater in F = (G*m1*m2)/r^2.
F = G Mstar M / d^2
F1 = G Mstar (4x)/x^2
F2 = G Mstar (3x)/(2x)^2
F1/F2 = (4/x )/ (3/4x) = 4/ (3/4) = 16/3
more than 4 times as much
(less mass and greater distance makes it really unnecessary to do the math :)