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Gravitational Field Strength - Need help please

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1. The gravitational field strength at the surface of the Earth is 6 times its value at the surface of the Moon. The mean density of the Moon is 0.6 times the mean density of the Earth.

Q. What is the value of the ratio (radius of Earth/radius of Moon)?

The correct answer is 3.6, however I do not know how to approach this question and require assistance.
2. My advice for approaching this question would be to first write down the equations for the density of the earth and moon, and also the gravitational field strength formula. From there you can solve use the information you are given to form two equations (one equation relating the densities, and one equation relating the gravitational field strengths). There are many routes from here to solving this problem, but I would suggest rearranging one of them for radius_earth/radius_moon and then solving the two equations as if they were simultaneous equations.

Give it a go, with this approach and see if you get the right answer. If you need anything else, let me know
3. (Original post by phyzard)
My advice for approaching this question would be to first write down the equations for the density of the earth and moon, and also the gravitational field strength formula. From there you can solve use the information you are given to form two equations (one equation relating the densities, and one equation relating the gravitational field strengths). There are many routes from here to solving this problem, but I would suggest rearranging one of them for radius_earth/radius_moon and then solving the two equations as if they were simultaneous equations.

Give it a go, with this approach and see if you get the right answer. If you need anything else, let me know
Alright, thanks for the response! I'll give it another go. Appreciate it though!

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