How to calculate gravitational constant

[tiny-tim]

Of course, the time unit that best matches with furlongs is fortnights, not hours.

The FFF system of units

oooh, thanks, jt … i'll definitely use fortnights in future! ​

i can't find any of the other units in the fff system …

lemmee see …

unit of angle: the farthing (= 90°, course )

unit of temperature: the fahrenheit

unit of charge: the flintstone

unit of energy: the sweetheart

unit of power: the fish! ​

any ideas for the unit of force?

 

[erok81]

To clarify, the sizes of the objects don't matter. Only their mass.

True the size doesn't matter, but where you find r from those masses does. Using from the surface or the center will give two different answers. I'm sure you know that, but maybe the the OP doesn't. Since distance and radius were both thrown around there may be some confusion.

To the OP, in this case you want to measure your r from the centers of each object you are using.

 

[FtlIsAwesome]

any ideas for the unit of force?

The falcon.

 

[FtlIsAwesome]

@robertroman10


In some cases people use kilometers instead of meters.

If this is so, then G will be:
6.67428x10^-20
Its units are N km²/kg²

When discussing the solar system, it is common list distances and other properties in kilometers. So check to make sure you haven't mixed meters and kilometers.

You will still get the same answer in Newtons.


This is the previous example using km.

Mass of Earth (kg): 6x10²⁴
Mass of Moon (kg): 7.3x10²²
Average distance between them (km): 384,000
Gravitational constant (N km²/kg²): 6.67428x10^-20

I get the exact same result of 2x10²⁰ N