I have a question on universal gravitation, it's sort of really hard, especially since i forgot some math rules.(adsbygoogle = window.adsbygoogle || []).push({});

At a certain point between the Earth and the Moon, the net gravitational force exerted on an object by Earth and the Moon is zero. The Earth-moon centre to centre separation is 3.84 x 10^8m. The mass of the moon is 1.2% the mass of the earth.

a) Where is this point located? Are there any such points?

I know there are points because theres an answer. Anyways heres what i did.

FG=0

GMem/(Re-m)^2=G x 0.012Me x m/(Rm-m)^2

After cancelling everything out. I do this:

1/(Re-m)^2= 0.012Me/(Rm-m)^2

Now i still have two unknowns so i solve for Rm-m

(3.84 x 10^8 - Re-m)^2= 0.012Re-m^2

Heres my problem i dont know how what to do with the bracket. If i expand it and then do quadratic formula i dont get the right answer.

So can anyone please help me and tell me if i did anything wrong.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Really need help

**Physics Forums | Science Articles, Homework Help, Discussion**